In a career that spanned more than fifty years, she appeared in such television programmes as: Coronation Street, Dixon of Dock Green, Z-Cars, Doctor Who, Little Britain, Emmerdale, Last of the Summer Wine, Crossroads, Gavin & Stacey and The Mighty Boosh.
Also in 2009, John appeared in The Vagina Monologues, before which her last theatre production was in the 1980s in Medea at London's Young Vic Theatre, opposite Dame Eileen Atkins.