Dot Cotton

Dot Cotton was either a fictional character on EastEnders, (PROSE: The Blood Cell) or a real individual who was an acquaintance of the Doctor. (TV: Dermot and the Doctor, Sprout Boy Meets a Galaxy of Stars)

Biography
The Doctor was a regular visitor to Dot's laundrette on Albert Square. While the Eleventh Doctor was trying to drop off Dermot O'Leary at the National Television Awards, Dermot stepped out of the TARDIS onto the square in front of Dot. (TV: Dermot and the Doctor)

She once met the Twelfth Doctor at a Christmas dinner party with Sprout Boy. (TV: Sprout Boy meets a Galaxy of Stars)

Behind the scenes

 * Clara's description of "famous Cockney chimney" refers to Dot being a well-known chainsmoker.
 * While she is arguably known most famously with her first married name of Cotton, she officially went by her second married name, Branning, from 2002 onwards.
 * She was played by June Brown, who played Lady Eleanor in The Time Warrior.