The daughter of the comedy actor Eric Barker and the actress Pearl Hackney, she grew up in the village of Stalisfield, Kent, and was educated at Ashford School.
[1] Barker trained at the Central School of Speech and Drama from 1960 to 1963,[2] in her final year winning the Carleton Hobbs Bursary, which gave her a six-month contract with the BBC's Radio Drama Company.
[3] In 1964 she joined the English Stage Company at the Royal Court Theatre for three plays: Inadmissible Evidence (understudy), Julius Caesar (crowd and understudy), and Cuckoo in the Nest, in which she played Rawlins.
[2] During four seasons with the National Theatre Company at the Old Vic Theatre between 1964 and 1968 she appeared in: Hobson's Choice (as Ada Figgins), Mother Courage and Her Children (Yvette), A Flea in her Ear (Eugenie), The Storm (Glasha), The Dance of Death (Jenny), Othello (Crowd), Juno and the Paycock (Neighbour), The Crucible (Mercy Lewis), Rosencrantz and Guildenstern are Dead (Courtier and Attendant), and Volpone (Androgyno).
She played Miss Prue in William Congreve's play Love for Love at the Old Vic Theatre with Laurence Olivier, directed by Peter Wood.