During her childhood, Kerr moved with her family from her birthplace in Scotland to Watford, Hertfordshire, where he father worked as a physiotherapist.

She made her theatrical debut at the Watford Palace Theatre, and later trained at the Central School of Speech and Drama in London.

[1] Frequent reference to Kerr is made in The Kenneth Williams Diaries (edited by Russell Davies).

Kerr and Williams were close friends, and worked together in several stage productions.

She died at the actors' retirement home Denville Hall, where she had been resident, in London on 23 September 2013, aged 93.