[3] When performing in one of her first radio shows, Terry-Thomas's Top of the Town, Karlin based some of the zany characters that she invented and played on people who had appeared before the rent tribunal chaired by her father.

[4][5] After training at RADA, Karlin made her stage debut for the Entertainments National Service Association (ENSA) in wartime shows, and subsequently appeared in repertory theatre and cabaret.

She appeared in the West End in Women of Twilight (1951–52), The Bad Seed (1955), The Diary of Anne Frank (1956–57), The Egg (1957–58), Fings Ain’t Wot They Used T’Be (1960–61), Fiddler on the Roof (1967–69), Bus Stop (1976), Torch Song Trilogy (1985-86) and Separate Tables (1993), among others.

[6] She made her film debut in Down Among the Z Men (1952), as well as featuring in A Touch of the Sun, Room at the Top, The Millionairess, Heavens Above!, Ladies Who Do, The Small World of Sammy Lee, The Bargee, Just like a Woman, A Clockwork Orange and Mahler (by Ken Russell).

In 1972, she appeared in the title role in Mother Courage and her Children at the Palace Theatre, Watford, in a production notable for the force of her performance, and its faithfulness to the Brechtian Verfremdungseffekt.

[13] A member of the Anti-Nazi League, she was prominent in protests against Holocaust denier David Irving, and campaigned to expose the Nazi sympathies of the Austrian politician Jörg Haider.