Her father, André van Gyseghem was an English actor and director of Belgian descent, and her mother, Jean Forbes-Robertson an actress.
In 1972, she played Olivia in Twelfth Night; Punch commented on her performance "veering from intimations of imperiousness to anticipations of lechery with great charm and fine technical control".
[1] In 1977, she appeared in two episodes of the drama series Secret Army in which she played Dorothy Neville.
Yvonne takes a romantic interest in Ted; Van Gyseghem thus played Taylor's love rival, as she had done in Duty Free.
In 1964 Van Gyseghem married actor Ralph Bates whom she met at university and starred alongside in many dramatic productions.