Olivia Livesy was born in 2002 to Sandra and Gordon Livesy. At some point between late 2008 and early 2009, Sandra took Liv and left Gordon to protect her daughter from him. She changed both she and Liv's surname to Flaherty so they couldn't be traced and Liv had no further contact with either Gordon or half-brother Aaron until 2016.
In February 2016, Liv approached Aaron in a park and asked him for some spare change, unaware of their relation. Later, Liv approached Aaron again and asked for more money for a cab, and stole his wallet. Robert Sugden managed to retrieve the wallet but Liv kicked him in the process. Aaron and Robert later visited Sandra but Liv answered the door. Liv believed Aaron and Robert had followed her home from the park, but Sandra revealed that Aaron was in fact her half brother. Aaron then covered for Liv when Sandra inquired how they met in the park.
While Aaron and Sandra were talking, Liv questioned Robert about her dad and asked him to give Gordon her number if he saw him, as she didn't believe the tale Sandra spun about her dad not wanting to know her. Liv was upset to walk in on Aaron asking Sandra why she covered for Gordon even though she knew about Gordon abusing him.
Liv managed to track Aaron down and scratched 'Liar' into the side of his car after reading about the case in the paper. She went to the court where she witnessed Gordon faking the side effects of his cancer treatment. The following day, Liv confronted Aaron about what he said about their dad, as she didn't believe him. Aaron figured out Liv was the one who scratched his car. Aaron sat Liv down and tried to explain what Gordon put him through but he couldn't admit he had been raped, so Liv didn't believe him. When Aaron was out of the room, Liv went through Aaron's mother Chas Dingle's phone and found Gordon's address. She later turned up at Gordon's address, but Aaron and Chas figured out where Liv went, and Aaron and Zak Dingle went chasing after her. Gordon insisted he didn't do anything to Aaron and told Liv that Aaron had self-harmed in the past. Gordon gave her his mother's necklace. When Aaron and Zak arrived, Liv apologised to Aaron. The following day she met up with Gordon and informed him that her mother went to the police.
A few weeks later Liv turned up at The Woolpack to stay with Aaron for a few days. She began spying on Aaron on Gordon's request. Liv recorded Aaron talking to Robert about Robert paying Ryan to lie about Gordon also abusing him. She was going to show Gordon the recording, but she overheard Aaron telling Chas about how much having Liv means to him and how they can trust her. She realised Gordon was manipulating her and didn't want to know her, but was only using her to get evidence for his defense. Liv admitted to Aaron and Chas she had been spying for Gordon, but she now believed him. Liv later returned home.
Liv took the stand during Gordon's trial, where Gordon's barrister quizzed her on what it was like to reunite with her dad and her relationship with him Liv struggled on the stand so the Judge decides to end it there for a day. Outside the court, Aaron found Liv trying to steal a bike. Liv admitted to Aaron that Gordon was only using her for the evidence she could give in the trial and asked her older brother if she could come and stay with him at The Woolpack. Liv wasn't pleased with Aaron's reaction, so she stormed off after telling Aaron she would get back on the stand and tell the jury everything, using the recording to back herself up. The following day Liv took the stand, and surprised everyone by backing up Aaron and not revealing the existence of the recording. She told the court Gordon was a liar, bully and a manipulator, and asked them not to allow Gordon to get away with what he did. Later Aaron thanked Liv, and Liv told him she deleted the recording. Aaron revealed that she was too hasty yesterday and would have allowed her to stay with him, but Liv explained so got carried away and her mum needed her. Neither Liv nor Sandra were present as Gordon was found guilty of all four charges that were brought against him.
Liv was brought to The Woolpack after being caught shoplifting and Liv told Aaron what things are like when her mother is stressed. Sandra came to collect Liv, but she was persuaded to allow Liv stay for a couple of weeks. Sandra decided to move to Dublin with Liv, but allows Liv to stay with Aaron on a more permanent basis after much convincing. She briefly becomes friends with fellow tearaway Gabby Thomas, but they have a falling-out after Gabby accuses Liv of having a crush on her own crush, Jacob Gallagher. Liv blames Aaron, as he joked that Liv and Jacob were flirting in David's, making Aaron realise just how hard raising teenager can be. Liv eventually patched things up with Gabby.
In May 2016, with the advent of Gordon's sentencing coming to pass, Liv wished to be there when it happened, but Aaron forbade her from going, which caused a rift between them. Simultaneously, Chas once again saw her scrambling through her bag, unaware she was having her first "monthly". Eventually, Aaron gave in to Liv's demands, and agreed to go to court with her for Gordon's sentencing. However, Liv, seeing just how much Aaron cares about her, decides not to go for his sake, as seeing Gordon again would push him over the edge. Liv begins to bond with Chas after the latter successfully concludes that she's having her first period, and acquires some sanitary products for her at a chemists'.
Liv comes to the conclusion that she needs to see her dad one last time and so rushes to court to witness Gordon get sent down. However, Robert quickly gives chase. She sits outside the court and Robert tells her that she can't just run off like this. Aaron then shows up and they agree to witness their dad sentenced. Gordon is sentenced to 18 years in prison. As he's led away by a guard, Liv throws the neckless Gordon gave to her and tells him that she hopes he dies in prison.
The day after Gordon's sentencing, Aaron receives news that his last name has officially been changed to "Dingle", so Chas and Aaron's distant cousin Charity hold a family do to celebrate. However, during the party, DS Wise take Liv, Aaron, and Chas into the back room, and reveal that Gordon has died. Liv practically breaks down, thinking it was her fault he died because of what she last said to him. Later on, she overhears a conversation between Chas and her brother Cain throw about the idea that Robert may have had Gordon killed in prison. Liv becomes determined to find out the true circumstances surrounding her dad's death, and when DS Wise pays a visit, she tries to tell him that Robert paid someone to have him killed, only for Wise to correct her by revealing that they've concluded Gordon killed himself; they found him hanging from a rope. Gordon leaves a fortune to Aaron and Liv, but Aaron turns it down, saying he doesn't want anything from him.
Despite Gordon's true fate revealed, she continues to feel animosity toward Robert, who happily reciprocates the antagonistic approach to her. Liv proves a handful for Aaron to deal with, as she's caught shoplifting in Hotten. Her frosty relationship with Robert gradually gets out of hand, to the point where they're both vying with Aaron to pick a side. Meanwhile, Liv has a cyber-bully stalker on her hands; she keeps receiving callous messages from someone claiming to be the late Gordon. She shows these messages to Gabby, who suggests it could be someone from school.
A date for Gordon's funeral is set. Aaron doesn't want to go, but says he'll be willing to if Liv wants to go. She initially says no, and her behaviour is further harmed due to the cyber-bullying. Aaron attributes this to the funeral, so he suggests that she come along with him and Robert to a theme park to take her mind off it. Liv refuses though, as she and Gabby already have plans. It's soon revealed that these "plans" include nicking some booze and going off to Gordon's house to trash it. Gabby's mum Bernice quickly uncovers these plans, and she and Chas break up the party, which has already started. Both Liv and Gabby got drunk, so Chas plans to make Liv pay by dragging her along to the house and cleaning it up, on the day of the funeral.
Liv decides she wants to go to the funeral after all, so Aaron bravely says he'll go with her. Chas and Robert also choose to come along, after the house-cleaning is finished. Liv and Robert once again get at each other's throats before she and Chas leave for Gordon's. While cleaning up outside the house, she meets with Ryan, the lad that Robert paid to lie about being a victim of Gordon, and she says that she knows what happened between him and Robert. Liv then offers Ryan £50,000 and Gordon's house to drop Robert in it and get him sent to prison. Ryan accepts the offer after initially rejecting it.
Later that day, Liv, Aaron, Chas, and Robert attend Gordon's funeral; unsurprisingly, they are the only guests. The speaker tells the group of Gordon's deep regret for all the things he did, which drives Liv to tears and she bails. Robert goes after her, and the two have a heart-to-heart, which makes Liv change her mind about her offer to Ryan and she tries to call him to tell him the deal's off, but the phone goes to voicemail, so she leaves him a message. Back home, she becomes nervous about Ryan, as he hasn't contacted her back yet, so she leaves him yet another message. Liv then tells Robert about these texts she's been getting, and it appears the two have finally put their differences aside, as Liv apologizes for all the things she accused Robert of. Liv then realises it's too late to call off the plan, as the police arrive and Robert is arrested. Liv confesses to Aaron the deal she made with Ryan, and she bursts into tears, thinking Aaron will hate her as he warns that Robert could go to prison for what she's done, but he assures Liv that he doesn't hate her. Liv overhears Robert arguing with Aaron after he learns that Liv dropped him in it and feeling guilty for the part she played, decides to run away. Robert soon tracks her down and the pair have another heart to heart during which Liv apologises and they agree to get on for Aaron's sake. Robert discovers the identity of Liv's cyber bully and puts an end to it. He and Aaron then take Liv on holiday.
Liv's relationship with Robert continudes to improve after she encourages him and Aaron to move in together. She is grateful when Robert saves Aaron's life following a car crash and is present at the hospital when Aaron comes round from his surgery and accepts Robert's marriage proposal. After Liv gets drunk with Gabby and Bernice threatens to get Chas' license revoked, she threatens to kick her out unless Aaron starts being tougher on her. Liv persuades Aaron to find them a place of their own and is delighted when he uses their inheritance money to buy The Mill. Liv enjoys her first Christmas with Aaron, Robert and the rest of the Dingles.
Liv spends a month in Ireland visiting her mum but upon her return, laments on how she spent most of her time caring for Sandra. Liv is disapppointed when no one remembers her birthday and lashes out at Aaron and Chas before storming out. Aaron finds her drowning her sorrows at the bridge and carries her home. The next day Liv confesses her fears that Aaron might hurt himself while in prison which he later relates to Robert and Chas. This prompts Robert to organise the wedding for the next day in order to prove his commitment to both Liv and Aaron. Liv assists in the preparation by overseeing the decorations at the Woolpack and is touched when Robert tells her the wedding is as much for her as it is for him and Aaron. The next day, Liv is devastated when Aaron is sentenced to 12 months in prison. She later asks Robert if he's going to send her away to her mum's but he gently assures her she's not going anywhere and hugs her close. After a visit to Aaron, Liv realises to her horror that her brother has been taking drugs in order to cope. He begs her not to tell Robert. Liv is excluded from school after coming to Gabby's defence and punching another student. After learning that Robert was unable to see Aaron due to an incident in the prison, Liv fears it's to do with the drugs and tells her brother in law everything.
In March 2017, Liv receives news that her mother has suffered an accident abroad and is on life support. Chas, who has only recently returned from taking a relative abroad for cancer treatment, opts to take Liv to see her mother.
Liv returns from Dublin mid September 2017 without Chas. Earlier on that day Aaron receives a phone call from Chas explaining that Liv is missing. Aaron packs a bag to go to Dublin to help look for Liv and Adam suggests he waits at home and calms down. Aaron prepares to leave when Liv arrives surprisingly at the door. Aaron is furious that Liv left Dublin and travelled back to Emmerdale on her own and without telling anyone. Liv tells Aaron that she knows about him and Robert Sugden breaking up as Gabby told her.
"Look at that, I got so excited, I almost hugged ya" - to Robert, after she learns Aaron has bought Mill Cottage.
"I'm gonna miss him so much" - to Robert, after Aaron is sentenced to 12 months imprisonment
- It was initially believed that Gordon and Sandra's child was born in mid to late 2006 as Aaron had been sent to live with his mum Chas for a while earlier in the year due to him being in contact with measles, which was harmful to pregnant Sandra. Despite this when the character was introduced in 2016, it was reported that Liv was a teenager and she was referred to as being 14 years old.