Kirsty "Dotty" Cotton is a fictional character from the BBC soap opera EastEnders, played by Molly Conlin from 2008 to 2010 and Milly Zero from 2019 to 2022.

Nick uses Dotty as his partner-in-crime; they plan to kill his mother Dot Branning (June Brown) and inherit the money from her will.

In her final storyline which aired on 23 February 2010, she left with her mother Sandy (Caroline Pegg), who she believed died.

[1] In December 2021, Sandy (Martha Cope) tells her that she is not Nick's daughter and that her father is Tom "Rocky" Cotton (Brian Conley).

[5][6] However, executive producer Diederick Santer praised Conlin for her portrayal of Dotty,[7] whilst both Brown and Altman opined that the storyline was one of their highlights.

[8][9] Dotty arrives in Walford on Christmas Day with Nick to see her estranged grandmother Dot Branning (June Brown).

[15] Dot holds a birthday party for Dotty, inviting Tiffany (Maisie Smith) and Liam Butcher (James Forde), but they do not want to attend.

[19] The next day, Dotty is left alone with Dot's husband Jim Branning (John Bardon) who is recovering from a stroke.

She explains that she wants to study in London, and attends the leaving party of Bex Fowler (Jasmine Armfield), and flirts with Tiffany's husband Keegan Baker (Zack Morris).

Dennis Rickman (Bleu Landau), Dotty's friend and colleague, dies on the boat, and she later discovers a voicemail that reveals Ian Beale (Adam Woodyatt) locked him in.

Dot moves to Ireland to live with Dotty's half-brother Charlie Cotton (Declan Bennett), leaving her step-granddaughter Sonia Fowler (Natalie Cassidy) in charge of her home.

Ruby Allen (Louisa Lytton) hires Dotty to work at her club when she drops out of university.

In 2021, Dotty has a one-night stand with her friend Vinny Panesar (Shiv Jalota); although he has feelings for her, she does not reciprocate them which puts a strain on their friendship.

Dotty's devious behaviour continues: she is infuriated when Sonia received power of attorney over Dot's money- wanting money to pay for her mother's rehab, she ropes her uncle Tom "Rocky" Cotton (Brian Conley) into pretending to be Sonia's long lost father in order to con her.

Dotty's manipulative behaviour makes her very unpopular, often finding herself between homes and often relying on Rocky or Sonia for accommodation.

Although she is unsuccessful in this, and Sonia pleads for her to stay, Dotty packs her bags and leaves in a taxi, parting on bad terms with her family and telling Walford to ‘go to hell’.

On 2 October 2008 it was reported that Nick Cotton, played by John Altman would return to EastEnders in Christmas 2008.

"[29] Conlin was considered too old for the part of Tiffany Dean which she had previously auditioned for but she succeeded in impressing the producers, who offered her the role of Dotty instead.

[33] The EastEnders website described her as "butter wouldn't melt when it comes to this cockney sparrow, but underneath she's a devil in disguise", as well as conniving, backstabbing and cold-hearted.

[37] Charlie Clements, who played Bradley Branning, said that Dotty, being Nick's daughter, was "bound to be a bit iffy.

"[40] On Holy Soap, Dotty is called a "demon child" and "sweetness and light" on the surface, "but underneath lurks a devil!".

[43] Jane Simon from the Daily Mirror criticised Dotty's accent and the storyline surrounding poisoning Dot.

This must not happen, simply because she gives me the willies more than anything else I've ever seen",[5] Simon similarly opined saying that she was glad to see Dotty leave.