Gabby is born on Christmas Day to Bernice Blackstock (Samantha Giles), and a DNA test later reveals Ashley Thomas (John Middleton) to be her father.

In Bernice's salon, Gabby discovers a sex tape of Kerry Wyatt (Laura Norton) and Dan Spencer (Liam Fox) and she shares it online.

Jacob later tells his father, David Metcalfe (Matthew Wolfenden), that Gabby and Lachlan White (Thomas Atkinson) broke into Eric Pollard's (Chris Chittell) house and took his ring.

Gabby and Liv Flaherty (Isobel Steele) break into Victoria Barton's (Isabel Hodgins) house and take her clothes.

Ashley and Laurel find out that Gabby is responsible for the robbery, as well as discovering that she has stolen Sandy Thomas' (Freddie Jones) pension.

Laurel decides to move Ashley into full time care, upsetting Gabby and Arthur.

Gabby begins to feel lonely, and feeling that Bernice's boyfriend, Liam Cavanagh (Jonny McPherson), and his new girlfriend, Leyla Harding (Roxy Shahidi) are responsible for Bernice leaving, she vandalises Leyla's wedding planning business, Take a Vow.

Gabby begins attending university, but comes to the conclusion that she does not enjoy it, and would rather be working to earn money.

Leyla later discovers that Gabby is behind the vandalism, and rather than reporting her to the police, she feels sympathy for her situation, and gives her a job at Take a Vow.

Gabby sees Liam chatting with his colleague Meena Jutla (Paige Sandhu) and decides to set the pair up.

Liam pleads with Leyla to see the truth, and when she realises that Gabby has become obsessed with her, she fires her from Take a Vow.

The pair later have sex, but after Jamie insists that it meant nothing and that he likes Dawn Taylor (Olivia Bromley), she decides to take revenge.

[13][14] Producer Iain MacLeod explained that despite the crushing extra blow for Gabby that was added in to make the story more realistic, she will come to realise that Ashley knew she loved him.

[13][14] Middleton praised Bentham, calling her "a lovely young woman" and said that he is proud of her and Clarke for their parts in the storyline.

[15] Following the conclusion of the storyline, Gabby was temporarily written out of the soap since Bentham was taking her GCSE exams in real life.

Daniel Kilkelly of Digital Spy described the situation as Gabby feeling as though people around her are distracted due to prioritising other things.

[17] The storyline sees Gabby taking out her anger on Leyla, since she blames her for breaking Bernice and Liam up.

[21] The fixation with Leyla concludes after her actions are discovered, with Leanna stating a "smear campaign" against Gabby.

[23] Bentham stated that Gabby sets her sights on Home Farm, the largest property in the village, owned by Kim.

[26] Bentham explained that some of Gabby's motives for the battle are impressing Kim and being jealous of Dawn's relationship with Jamie.

Bentham enthused at the thought of Gabby taking over Home Farm, since it would "launch her into something completely new and exciting".

Bentham added that due to Kim buying the baby gifts early into the pregnancy, Gabby gets a taste of the Home Farm life, and it leads her to want more.

[28] In episodes broadcast in February 2016, Gabby was seen drawing on a Scouse brow with permanent marker as part of her under-age drinking storyline.

[29] A columnist for Inside Soap commented: "Gabby Thomas isn't a bad girl, but she really ought to think twice before listening to sneaky Lachlan.

"[30] Duncan Lindsay of Metro praised Bentham and her on-screen family for the portrayal of Ashley's dementia, saying their performances "continue to be outstanding".

[32] In 2016, Sarah Ellis from Inside Soap criticised Gabby's behaviour, saying that it is the "last thing poor Ashley needs".