Elsie Ferguson

In the short story The Adventure of the Cheap Flat, Elsie Ferguson was the friend of Stella Robinson. Elsie had gone to the cheap flat at Montagu Mansions ahead of the Robinsons and was told that it had already been rented out. She hurried down the stairs and met the Robinsons who had just arrived. She told them that the flat had already been let.

Portrayals
Elsie Ferguson was played by Jemma Churchill in the film adaptation of The Adventure of the Cheap Flat in Series 2 of ITV's Agatha Christie's Poirot. There she was credited simply as "Elsie" and in her interaction with the Robinsons, there was no indication that they were friends.