She was born in London, the daughter of Nicholas "Beau" Hannen, who was also an actor on the stage and in film.

Sir Nicholas died in office and marines from HMS Hermione served as an honour guard and pallbearers at his funeral.

[1] On her mother's side she was the grand-daughter of Sir Henry Morland, a British administrator in the Bombay Presidency of India.

Marie was married to the Italian nobleman, Jerome Carandini, the Marquis of Sarzano, and thus Hannen was also a distant cousin of the actor Christopher Lee.

In the 1930s, she acted in numerous plays performed at the Old Vic in London, including The Voysey Inheritance, The Rivals, Man and Superman and Hamlet.