Gabby was born into controversy, as no one had any idea whether Ashley or Bernice's former lover Carlos Diaz was her biological father. Tests soon proved Ashley's paternity. He and Bernice reconciled, but Bernice struggled with motherhood, a struggle which made her leave the village when Gabby was just a few months old.
Ashley lived as a single father for several years, until he began dating Laurel Potts, finally marrying her in 2005. Laurel became the primary maternal figure in Gabby's life, and Gabby also gained more additions to her family with the arrivals of grandfather Sandy Thomas, cousin Jasmine Thomas, and in 2007, a half-brother, Daniel Thomas. Gabby's life was thrown into turmoil when Daniel died several months later, and Laurel and Ashley were torn apart over the news that Arthur Doland was actually their biological son, switched at birth. Gabby felt ignored, and began acting out after seeing her parents in constant conflict. After Arthur became a part of the family, things settled down.
More turmoil hit the family in 2012 when Laurel broke up with Ashley due to his abuse of Sandy. She eventually began dating Marlon Dingle, while Ashley eventually became homeless. Gabby lashed out at Marlon. Further complicating matters was the return of Bernice after a decade away, now wanting to spend more time with Gabby. As a result the family splintered between Laurel, Bernice, and eventually Ashley's new relationship with Harriet Finch.
Gabby became a vegetarian, although she confessed to Ashley that she did this partly to annoy Bernice.
In 2015, Gabby was traumatised when a drunken Laurel picked her up from school, calling her a "bitch," and later, erroneously telling her Ashley had died after a car accident. Bernice began dating, and later married, Lawrence White, delighting Gabby, who saw the perfect opportunity for lots of expensive presents. She and Bernice moved into Home Farm, where Lachlan White roped a guilt-ridden Gabby into a revenge plot against Eric Pollard. As the year closed, Ashley began trying to spend more time with her, and reconciled with a now-recovering alcoholic Laurel.
In 2016, Gabby was upset to learn Ashley had dementia. Gabby posted a sex tape of Dan and Kerry Spencer causing them to be very embarrassed and Gabby was forced to clean the salon. Also after Bernice refused to do Gabby's eyebrows Gabby drew an hideous Scouse brow in permanent marker. Gabby became rebellious and started drinking. This was revealed after Ashley found vodka in a water bottle and blamed it on Laurel causing the pair to fall out. Gabby had to clean the pub as punishment. Gabby later developed feelings for Jacob Gallagher and on their first date she told him about what her and Lachlan did to Eric and Jacob got angry and told Gabby to leave before telling David Metcalfe and Leyla Harding. David then confronted Gabby, Lachlan and their family. Jacob managed to stop David from calling the police but Lawrence took the matter of punishment into his own hands. Gabby and Jacob later made up and after convincing Jacob to steal alcohol from the shop they head down to the pavilion to play and drinking game before sharing a kiss. Eric later sees Gabby stumbling up Main Street and finds Jacob's phone by the bottle. Gabby is grounded by Laurel and Ashley and Jacob and Gabby aren't allowed to see each other.
Gabby befriends Liv Flaherty as Gabby takes Liv to town to get school clothes. After something Liv's half brother Aaron Dingle says about Liv having crush on Jacob, Gabby is horrible to Liv because she thinks she has a crush on Jacob. They make up and hang out at Home Farm lot. Liv then tells Gabby about messages of hate she's been getting from someone pretending to be her dead father Gordon Livesy. The day before Gordon's funeral, Liv and Gabby hold a house smashing party at Gordon's house which was left to Liv to express how much they hate Gordon after raped Aaron numerous occasions. Bernice and Chas Dingle drag them home. Gabby is sick on Bernice's shoe as she is drunk.
In early July 2016, Jacob and Gabby went round to Mulberry Cottage and got drunk by drinking far too much vodka. Jacob pulled a condom from his bag. They nearly went upstairs and had sex but got caught in the act by Laurel. An angry Laurel dragged them both round to Home Farm and told David Metcalfe and also Leyla Harding to meet her there. Bernice laid down the law to both off them. She said that they are only allowed to see each other at school, they are no longer allowed to chat with each other over the Internet and the are not allowed to go out together again. Jacob tells Leyla that he got the condom from David's wallet, so she has a look in his wallet and pulls out six condoms. Then Gabby revealed to everyone that Laurel hurt Jacob by showing everyone that Jacob has bruises on his arm.