In 2014, Harriet befriends Dom Andrews and helps his daughter Gemma with a school project. When Gemma goes missing, Harriet, Ashley and many other locals help Dom find her. Harriet is the person who spots Gemma lying in a ditch, and demands that Zak Dingle calls for an ambulance. Harriet goes to the hospital with Dom and is devastated when the doctors reveal that Gemma has died. Harriet tries to help Dom through his grief, but he is having none of it and throws her out of his house. Harriet is the vicar who performs Gemma's funeral later in March. Dom later apologises to her for his actions.
In July 2014, Harriet becomes curious when Ashley begins talking about a woman he met named Carole. Harriet believes that Ashley is making Carole up, so she texts Carole from Ashley's mobile phone to meet him in Emmerdale village. Harriet is later shocked when Carole arrives in Emmerdale and is jealous as she secretly has feelings for Ashley. In December 2014, Harriet officiates an unauthorized wedding blessing for Ruby Haswell and Ali Spencer at St. Mary's church and is later sacked by the bishop. However in April 2016, Harriet is reinstated as vicar of St.Mary's Church, after Ashley retires following his diagnosis with dementia. In May 2016 Harriet is devastated to hear that Edna Birch has died of ovarian cancer.
In 2017, she falls for local bad boy Cain Dingle and the pair begin a secret and steamy affair. Cain calls it off with her because he didn't want her to get hurt down the line and was scared of falling deeper for her. However, Harriet is then stabbed by two drug dealers during an altercation. Thankfully, Finn Barton calls an ambulance and Harriet is rushed to hospital, where she recovers.Cain hears about this and realizes his true feelings for her, nearly killing Ross Barton for his involvement. As Harriet wakes from her coma, she finds Cain by her bedside. Asking "Why are you here?" he takes her hand and responds with "Why do you think?". He then lovingly kisses it as Moira Barton and Emma Barton look on, confirming their relationship.
In October 2017, Moira gives birth to Cains son Isaac and Harriet selflessly tells Cain he belongs with her and that he needs to be there to support Moira and his son. Harriet declares her love for Cain before walking out and leaving him. Later that month, Cain overhears Harriet telling Ross she's considering moving to Oxford to a new parish. Cain tries to talk Harriet round to staying and tells her he doesn't want her to go. They end up sharing a passionate kiss before Harriet pulls away and walks off.
In November 2017, Harriet returns from Oxford and Cain greets her. She has to remind Cain they are no longer together and there is no 'us' anymore. Cain later follows her to the church and insists there is still an 'us'. She tells Cain that Moira needs him but he demands he doesn't need Moira, He needs her. Cain tries to talk Harriet around and they end up sharing another passionate kiss. Harriet continues to remind Cain he belongs with Moira but he tells Harriet he belongs with her now. Harriet dismisses Cain and he angrily storms off. A few days later, Harriet calls round to see Cain and he is looking after Isaac. She is concerned about him and when Cain asks why, she insists she still cares about him as a friend which prompts Cain to snap at her, Harriet storms off, upset and hurt. Harriet walks back into the Woolpack later on and Cain apologizes for the way he spoke to her. She asks if they can still be friends, he said that's not what he's thinking and they end up kissing. They are back together.
"I'm up for a quick one, if you like. A chat, obviously." (first line)
"Step back unless you want to get insulted."
"Kickass vicar and her nerdy sidekick."
"Oh... and I would love to give you one. Didn't mean that how it sounded."
"We all have buttons, you just need to know which ones to press."
"I have a faulty motor. Someone needs to get it turning, it may as well be you."