At ten, Baker made her debut at the Opera House, Tunbridge Wells, and continued to tour as a single variety act — singing, dancing and performing impersonations.

Her stage act included a gossip from the North of England, with a silent, sullen companion named "Big Cynthia", almost always played by a man in drag (such as Victor Graham, and lastly by Matthew Kelly).

She also appeared in films, including Karel Reisz's Saturday Night and Sunday Morning (1960), Up the Junction (1968), and playing Mrs. Sowerberry in the musical Oliver!

Playing her brother Eli was the comedian Jimmy Jewel and the series was centred on their characters' love-hate relationship as they tried to run their small family business, Pledge's Purer Pickles.

After suing the production company for an on-set injury in which she broke her leg (after slipping on beer on the set), the series ended, as did her television acting career.

[10] Her final television appearance came the same year in an episode of the BBC arts documentary show Omnibus about comedians, broadcast on 28 December 1978.

[3] On Christmas Eve 1961, Baker was hit by a passing car that mounted the pavement in London's Charing Cross Road, not far from her home at Ridgmount Gardens in Bloomsbury.

In 1974–75, while working on Not on Your Nellie, Baker's cognitive decline deepened, which necessitated her to have a stronger reliance on cue cards, and she often failed to show up for rehearsals.

[3] Baker was diagnosed with Alzheimer's disease in her early seventies, and at age 76 in 1981 she moved to Brinsworth House, the retirement home for performers, in Twickenham, London.

[3] Actress Jean Fergusson, known for appearances in Last of the Summer Wine, wrote a biography and devised and starred in a tribute show, She Knows Y' Know!, at London's Vaudeville Theatre in 1997.