Her guardians, Gwen (Eve Myles/Gwenllian Davies) and Will (Dafydd Emyr), wished to adopt her, but Dot returned to Walford after Will's death and spent the rest of her childhood helping her neglectful mother care for her younger half-siblings: Gerry, Tim and Rose (Polly Perkins).

The following year, he forced her to have an abortion, threatening to leave her if she did not; in desperation, Dot approached Dr. Harold Legg (Leonard Fenton), who reluctantly performed the procedure by inducing birth.

Dot is introduced as the gossiping, chain smoking, Christian friend of Ethel Skinner (Gretchen Franklin) and Lou Beale (Anna Wing) who works with Pauline Fowler (Wendy Richard) at the Walford launderette.

After Nick is cleared of murder, his girlfriend Zoe Newton (Elizabeth Chadwick) arrives in Walford and introduces Dot to their nine-year-old son, Ashley Cotton (Rossi Higgins).

Dot remains adamant to see the best in Nick until he confesses to the one crime he never told her about; the murder of her old friend Reg Cox (Johnnie Clayton), who was alleged to have died by accident nearly three decades ago.

She finds a Christmas mixtape recorded by her dead friend Heather Trott (Cheryl Fergison), and takes in a stray cat, which she eventually names Dave.

[11] Brown has told Decca Aitkenhead of The Guardian in 2009 that she was wary of joining a soap opera as she had seen EastEnders once on television, "and there was an argument going on, and I thought, 'Oh, I don't want to watch all that,' so I switched it off.

Eagle-eyed, she patrols the Square, confronting evil and despair and asking those stricken with doubt to trust God, while simultaneously organizing the local Neighbourhood Watch scheme.

[29] Upon her arrival, Dot Cotton was quickly established as the gossip, whose purpose, as author Anthony Slide sees it, was "that of a Greek chorus, commenting on the foibles of her fellow residents of Albert Square, from her vantage point as manager of the local launderette".

[19] The "gossip" is a soap opera role that author Christine Geraghty has described as "crucial to the audience's engagement with a serial and provides both a source of information and a means of speculation for the viewer.

[30] According to Gary Loach from GaydarNation, Dot was being used by the programme makers to expose the bigotry of the "moral majority" in the real world following a public and media backlash over EastEnders' screening of its first homosexual kiss.

[30] However, while Dot has portrayed bigotry, author Anthony Slide has noted that the character can typically be "relied upon to drop her prejudices – she learned to accept both blacks and homosexuals in Albert Square.

"[34] With the help of a fake priest, Nick managed to convince his mother of his new-found faith and then began a slow campaign to control her eating habits and poison her in order to claim her money.

Then followed a plot that saw him largely responsible for the death of his son Ashley (Frankie Fitzgerald) in June 2001, ultimately leading Dot to disown Nick and prompting to leave the Square again.

[39] Dot finally succumbed and accepted his marriage proposal in an episode that aired in December 2001; the scenes were filmed inside one of the carriages of the London Eye on the South Bank of the River Thames.

The Guardian critic, Nancy Banks-Smith, described the wedding as "uniquely uneventful [...] For Dot and Jim 'In sickness and health... till death do us part' seemed to carry more resonance than for most.

A source told the Daily Mirror: "Dot's been struggling for a while and realises that she can no longer give Jim the care and attention he deserves and is forced to make the heartbreaking decision that he should move into a home.

"[51] Critic for The Guardian, Nancy Banks-Smith, discussed the characters' relationship in 2008, comparing them to the girls written about by Dylan Thomas: "There was always one pretty and pert [Ethel], and always one in glasses [Dot]."

She compares Ethel and Dot's function in EastEnders to the trio of Ena Sharples, Minnie Caldwell and Martha Longhurst from Coronation Street with regard to providing humour.

[52] The author goes on to note that Ethel's role in Dot's narrative was difficult to replace because "far from being complete stereotypes, their relationships depend on them being long-standing friends with the ability to share stories and reminisce.

[22] As with Ethel, Dot and Pauline's friendship was often used for comedic purposes; emphasis was placed on their differences, leading to numerous petty squabbles and in 2004 saw them "buried alive" underneath a collapsed fairground ride, in the midst of a cake-selling war.

The storyline allowed the production team to present all sides of the debate about euthanasia, from the perspective of the sufferer and from the person who is asked to assist in the mercy killing, religious and moral opposition.

Riddled with an intolerable burden of guilt, she felt there was only one person she could talk to [Jesus] The Dot and Ethel storyline played out in over four months with many similar scenes, to an average audience of 16 million viewers.

[76] On 20 February 2020, it was reported that Dot's appearance on 21 January 2020 was her last and that Brown had announced that she would "never go back" when she told the Distinct Nostalgia podcast, "I don't want a retainer for EastEnders, I've left.

Dr Indarjit Singh, editor of the Sikh Messenger and patron of the World Congress of Faiths suggested that Dot's endless quoting from the Bible served to ridicule religion.

The BBC responded, "EastEnders aims to reflect real life, and this means including and telling stories about characters from many different backgrounds, faiths, religions and sexualities.

The Guardian' Nancy Banks-Smith deemed Brown possibly the only member of the cast with the exception of Barbara Windsor (Peggy Mitchell) capable of carrying such a monologue.

"[101] Conversely, Tim Teeman posed the question in The Times: "I know she's a national institution and June Brown plays her like a dream, but was last night's Dot Cotton extravaganza really that great?

[106] In 2020, Sara Wallis and Ian Hyland from The Daily Mirror placed Kat sixth on their ranked list of the best EastEnders characters of all time, calling Dot a "Legendary, perfectly-coiffed, chain-smoking busybody" and a "tragicomic icon" who had "put up with plenty over the years".

[112][113] She has also inspired catwalk themes, such as that of aspiring designer Hollie Luxton in 2007, who stated, "I wanted to capture the nostalgia of the bygone days and play with the idea of clothing coming out of the wash misshapen and faded.