Ursula Bourne

In the novel The Murder of Roger Ackroyd, Ursula Bourne (married name Paton) is Roger Ackroyd's parlourmaid. She is a lady of an Irish family of nobility. Having a family of seven sisters, she was forced into service through poverty.

She was Mrs Folliott's younger sister. Mrs Folliott helped Ursula by providing references.

Spoilers ahead
Ursula is secretly married to Ralph Paton and is fired when she tells Ackroyd of this. In the night of Ackroyd’s death, she went to a small hut in the garden to talk to Ralph, where she accidentally left a proof of her being there. Ackroyd’s lawyer, Mr Hammond, finds out that some money of his is missing and maid Elsie Dale thinks that the thief was Ursula Bourne. However, the fourty pounds were taken by Flora Ackroyd.

Agatha Christie's Poirot
In Agatha Christie's Poirot, Ursula was portrayed by Daisy Beaumont. Here she is first seen pouring tea into Flora Ackroyd's cup when the latter's mother makes a remark about how she was getting engaged to Ralph and makes Ursula spill the tea. She later appears when Poirot and Japp talk to her and Poirot notices that a piece of her apron was cut. As in the original novel she announces her marriage to Ralph at the end making her part one of the most accurate portrayals of the episode.