Doris Sims

In the novel Three Act Tragedy, Doris Sims is a girl who works at Abrosine, Ltd, the Brook Street dress shop owned by Cynthia Dacres.

Hermione "Egg" Lytton Gore approaches Doris, and asks her about her job and her employer, saying that she is writing an article about various professions for women. Doris is of the opinion that the business is not doing well financially, and that Mrs Dacres has been borrowing money, and has gotten into debt.

Doris also believes that Mrs Dacres is still keen on her husband, although none of the other girls who work at Ambrosine agree with her. She tells Egg that there has been talk among the girls of a rich young man who might have put things right with the business. However, he was suddenly ordered to take a sea voyage by Sir Bartholomew Strange.

Portrayals
Doris is not featured in Murder in Three Acts (1986), although there are several models and salespersons working at the dress shop belonging to Cynthia Dayton (the name of the Cynthia Dacres character in this adaptation).

As for the film adaptation of Three Act Tragedy in Series 12 of ITV's Agatha Christie's Poirot drama series, IMDB reports that there is one "Doris", an uncredited part played by Kimberley Stewart, an actress and fashion model. She is probably the blonde model, the last one to appear during the viewing Mrs Dacres hosted for "Egg".