Jessie (The Cornish Mystery)

In the short story The Cornish Mystery, Jessie was the maid of the Pengelleys at Polgarwith. Poirot and Hastings met her at the Pengelley's house just half an hour after Mrs Pengelley had died. While Jessie kept insisting that wasn't her place to say anything and she wasn't going to, she told them about her seeing her master with taking down a can of weedkiller from the shelf while her mistress's gruel was on the table. He had jumped when he notice Jessie watching. "For a girl who was not going to say anything, that girl said a lot," Hasting noted after meeting her. During the trial of Edward Pengelley, Jessie "poured out a flood of voluble information, most of which was rejected, but which certainly strengthened the case against the prisoner", although what she said was not detailed.

Portrayals
Jessie was played by Tilly Vosburgh in the film adaptation of the story in episode 4 of Series 2 of ITV's Agatha Christie's Poirot drama series. In the film credits, her name was given as "Jessie Dawlish". This surname was not mentioned in the original story. Jessie gets an entire scene on the witness stand at the trial where she described in detail how she saw Edward Pengelley put weed killer into Mrs Pengelley's gruel. There is not indication that this was "rejected" like in the orginal story.