Beach won a scholarship to RADA at the age of 16. After leaving, she toured with Frankie Howerd in Hotel Paradiso, and then came to London in the title role of Emlyn Williams's Beth. This was not a success, but she was soon busily engaged in television work, until she returned to the stage in the Theatre Workshop company at the Theatre Royal Stratford East. Among the parts she played there were Rosie in Fings Ain't Wot They Used T'Be, and Miss Gilchrist in The Hostage. She then played Barbara in Billy Liar at the Cambridge Theatre in September 1960. She was also a member of the BBC's Radio Drama Company.