She was born in Scarborough, Yorkshire, England, and had a successful stage career before breaking into television. Her West End debut was opposite Sir Ralph Richardson. Her television career began in 1972, playing Vivie Warren in Mrs. Warren's Profession opposite Robert Powell. Despite several major TV roles, including two of the BBC Television Shakespeare productions (as Desdemona in Othello and Regan in King Lear), she did not become a household name until she appeared with Richard Briers in the 1984 sitcom, Ever Decreasing Circles.
From 1975 to 1984, she was married to the actor, Daniel Massey (who, following their divorce, married her sister). In 1991, she married Ian Holm, and they appeared together as Pod and Homily in the BBC's 1993 adaptation of The Borrowers. Her few film appearances include Cry Freedom (1987) and Iris (2001).