Rosalie Tamplin

In the Hercule Poirot novel The Mystery of the Blue Train, Lady Rosalie Tamplin is the mother of Lenox and the wife of Charles Evans. She is described as a "golden haired, blue eyed lady. The forty-four Lady Tamplin could still rank as a beauty".

She is a cousin of Katherine Grey. She lives in Villa Marguerite, French Riviera. Rosalie is a well-known figure in the French Riviera because of the parties she hosts.

She had four husbands so far: the first was "merely an indiscretion". After the latter died, Lady Tamplin married a rich manufacturer which died within three years. She then married Viscount Tamplin, and even though he died, Lady Tamplin kept his last name even after marrying Charles Evans.

Her fourth husband is financially dependent on her.

Portrayals
In the 2005 Agatha Christie's Poirot episode based off The Mystery of the Blue Train, she was portrayed by actress Lindsay Duncan. Unlike the original novel, here she was actually onboard the Train Bleu, whereas in the original novel she was in Villa Marguerite at the time of Ruth's murder.