Another unusual Unsung Hero. Annabel has only one single credit listed on IMDb, her 1959 role as Marie-Noel in Scapegoat with Alec Guinness. Not much is known about her. There seems to be literally no record of what happened to her.
I nominate her because her acting ability in Scapegoat was exceptional. She steals every scene with a charming and innocent persona that melts your heart.
[EDIT] I did some research and found out more about Annabel. She was the daughter of actor Basil Bartlett and great-granddaughter of actress Lilly Langtry.