Carla Lemarchant

In the novel Five Little Pigs, Caroline “Carla” Lemarchant (born Crale) is the daughter of Caroline and Amyas Crale. She is described as a "tall, slender young woman in the early twenties; the  kind  of  young  woman  that  one  definitely  looked at twice. Her  head  was  well  poised  on  her  shoulders,  she had a square brow, a sensitively cut nose, and a determined chin". She wants to know if her mother really did murder her father, so she contacts Hercule Poirot.

She is engaged to John Rattery.

TV Portrayals
In the ITV Agatha Christie's Poirot episode, Carla is renamed Lucy Lemarchant. In this version, she tries to kill the murderer of the case but then Poirot makes her change idea and put her revolver down.