Collins was educated at Sacred Heart High School. She studied at the Central School of Speech and Drama in London. She worked as a teacher until 1962. She then made her stage debut at Windsor in "A Gazelle in Park Lane". In 1965, she made her West End debut in "Passion Flower Hotel". During the play's run, she made her first movie, "Secrets of a Windmill Girl". It was released in 1966.