In the novel A Caribbean Mystery, Esther Walters (later Anderson) was the secretary of Mr Rafiel. She travelled with him on his vacation to St Honoré. Her late husband was a wastrel and did little to support his family. He stepped in front of a bus while drunk and was killed. Esther was left to look after a daughter. Mr Rafiel subsequently made himself responsible for Esther's daughter's schooling and paid for her to be educated at a boarding school.
In the 1983 Warner Bros adaptation of A Caribbean Mystery, her name is "Ruth Walter". Here she is a trained nurse. She introduces herself as Mr Rafiel's "nurse, secretary and entertainment manager". The part of Ruth Walter is played by Swoosie Kurtz. In this adaptation, she is the one who makes the observation to Miss Marple that Molly didn't take enough of the sleeping pills to cause any harm. "She had it timed right to the minute", almost as if she had staged the event. Dr Grahame confirms this puzzling observation. She is also the one who fills in Miss Marple about Molly Kendal's family background.
In the BBC 1989 adaptation of A Caribbean Mystery, Esther Walters is portrayed by Barbara Barnes.
In the 2013 ITV adaptation of A Caribbean Mystery, Esther Walters is portrayed by Montserrat Lombard.