[1] Her Polish father met her Scottish mother, a teacher of English, when he was stationed in Greenock during the Second World War.
She appeared in Casualty, The Crow Road, Dalziel and Pascoe, The Inspector Lynley Mysteries, Foyle's War, Outnumbered and Lewis.
In 1989 she appeared as Ophelia in the National Theatre production of Hamlet, with the title role being played by Daniel Day-Lewis, Ian Charleson and finally Jeremy Northam.
Collaborating with Chilean filmmaker Pablo Larraín, Gonet appeared in the films Spencer (2021) and El Conde (2023) as Queen Elizabeth II and Margaret Thatcher respectively.
The couple co-starred in an episode of Roman Mysteries as Queen Berenice of Judea and Emperor Titus, and as Mr. and Mrs. Musgrove in ITV's 2007 production of Jane Austen's Persuasion, and they both participated in a 2001 Shakespeare's Richard III audiobook.