Laffin made her major film debut in 1977, gaining critical acclaim for her role in Jacques Doillon's 1979 film, La Femme qui pleure.

That same year, she co-starred with a young Roberto Benigni in the film Chiedo asilo.

Her career was cut short at the age of 33 by a massive heart attack.

Her daughter later said that she believed Laffin had committed suicide, but says that she has not been able to confirm this either way.

[1] During her short career, Laffin appeared with many of France's rising young stars, including Gérard Depardieu, Juliette Binoche and Miou-Miou, and established stars such as Yves Montand.