Lyon was only 14 years old when she played against James Mason in "Lolita", which is based on a controversial novel by Vladimir Nabokov about a man's obsession with a teenage girl. The film would also create debate, not least because of Lyon's age. She was awarded a Golden Globe as the best female newcomer for her role in the film.

Lyon starred in about 20 films and television series during his career, including in "The Night of the Iguanan", "Evel Knievel" and "Tony Rome".