Muscle Beach Party (25 Mar 1964) beach girl
Definitely not Maureen O’Connor from 1938.
Possibly Maureen O’Connor singer and vocal coach
After an un-credited role in Expresso Bongo (1959), Maureen O’Connor was cast as one of the students in Werewolf in a Girl’s Dormitory (1961), and then as a beach girl in Muscle Beach Party (1964). She had a recurring role as a secretary in Dean Martin’s TV series Matt Houston (1982-1985), and made her last feature film appearance in The Man Who Loved Women (1983).