Eva Kane

In the novel Mrs McGinty's Dead, Eva Kane had an affair with a married man. She inspired the man to murder his wife and bury her in a cellar.

Eva had a child, Evelyn Hope, who Hercule Poirot presumed was a girl. The child was adopted by someone in Broadhinny. It turned out that the child was a boy.

Portrayals
In the Agatha Christie's Poirot episode Mrs McGinty's Dead, Eva Kane appears only in a picture but her portrayal is faithful to the original one.

In Mademoiselle Mac Ginty est morte, the France Télévisions adaptation of the novel, the parallel character is named Eva Mauduis who also had a child whom everyone presumed it was a girl. In this case it isn't because Evelyn was both a male and female name. The truth was discovered by consulting newspaper archives.