Diana Lee carried on a family tradition of "ghost singing". Like both of her parents, she often "ghost sang", providing the voice of actors in movies.
She was the singing voice of Samantha Eggar in Doctor Dolittle (1967), Diana Sowle in Willy Wonka & the Chocolate Factory (1971) and Liv Ullmann in Lost Horizon (1973).
Like Frank and Nancy Sinatra she sang together with her father Bill Lee in 1968 the song 'Something Stupid'.