Sally Thomsett

In 1970, Thomsett was cast as the 11-year-old Phyllis despite being 20 years old at the time, two years older than Jenny Agutter, who played her elder sister, Bobbie. Her contract forbade her from revealing her true age during the making of the film, and she was not allowed to be seen smoking, drinking, driving her car or in the company of her boyfriend during the shoot.[4][5] However, she did have experience playing girls, and the Edwardian smocks disguised her bust. Even the film crew were unaware of her age, and they gave her sweets while treating Agutter as nearly an adult.[6] During an appearance on a BBC children's television programme shortly after, Thomsett was told, "I wouldn't dream of asking a lady her age, but you're obviously quite a bit older than the part you played in the film." She received a nomination for the BAFTA Film Award for Newcomer to Leading Film Roles.

Thomsett went on to appear in The Fenn Street Gang and Softly, Softly: Task Force before starring in the psychological thriller film Straw Dogs opposite Dustin Hoffman and Susan George, as well as Baxter! with Britt Ekland. After appearing in a television commercial advertising Bovril in 1972, Thomsett was spotted by directors Brian Cooke and Johnnie Mortimer, who cast her in the hit ITV sitcom Man About the House as Jo, a role that she played for the show's entire run from 1973 to 1976, including a 1974 spin-off film of the same name.

After Man About the House ended in 1976, Thomsett continued to act, appearing in Wodehouse Playhouse in 1978. After appearing in a Crunchie chocolate bars advert in 1979, Thomsett gave up acting for a while in order to travel the world. She returned in the mid-1980s and appeared on stage in a 1987 production of The Cat and the Canary[7] before making regular pantomime appearances. She also appeared in the music video for Doctor in Distress, a charity single made to save Doctor Who from cancellation in 1985.[8] Thomsett's career slowed down after the birth of her daughter, although she did appear on stage in 1998 and 1999 in a touring production of The Holly and the Ivy.

Although she now rarely acts, Thomsett appeared in Peter Pan as Mrs. Darling at Doncaster Racecourse during the 2014-2015 Christmas season.[9] She also occasionally appears at fan conventions.

It was announced in February 2021 that Thomsett would be returning to the screen after several decades, playing one of the lead roles in Together, a television comedy created and written by CJ De Mooi. This will mark her first acting appearance since 1978.