The acting career of Elspet Gray, who has died aged 83, was obscured but not extinguished by being so closely bound up with her marriage to the farceur Brian Rix. In 1951, Gray gave birth to a daughter, Shelley, who had Down's syndrome. In later life she was active alongside her actor-manager husband after he left the stage in 1977 to work for people with learning disabilities – initially through presenting a BBC television series, and then as secretary general of Mencap. However, she made periodic returns to the stage and maintained a screen presence: in 1979, for instance, she was a paediatrician guest in Fawlty Towers, and in 1994 the first bride's mother in Four Weddings and a Funeral.
As well as bringing up her subsequent three children, she visited Shelley every week in the residential home that she went to after the family had done their best to "muddle through" for five years. Both Gray and Rix had feelings of guilt about sending their child away, though they reckoned that she would get better attention in the residential home, and that it would be unkind to expose her to the attention she would have received had she been with her famous parents.
Rix, the leading exponent of farce in British theatre, television and cinema of the period, became an energetic campaigner and fundraiser, and Gray a powerful advocate for their cause. The current chief executive of Mencap, Mark Goldring, said that the eventual Lord and Lady Rix "made a formidable team in their determination to change the lives of people with learning disabilities".
The couple returned to the stage in a revival of the popular farce Dry Rot in 1988, and five years later in a presentation called Tour de Farce, describing the trials and tribulations of travelling players at various stages of history. Some of the material in Tour de Farce might have been regarded as on the bawdy side for the dignified and beautiful Gray, including the anecdote about a notice in one theatre warning the chorus girls that squatting on the wash basins to relieve themselves might cause a nasty accident: "Ladies have been badly lacerated."
But Gray and her husband had always been an unconventional couple. Rix, who came from a wealthy family, was running his own theatre company when, aged 25, he auditioned her. He recalled later that it had been a miserably cold and damp day and that he had a hangover, but he had been besotted immediately as she walked in and illuminated the scene. Years later he still remembered exactly what she had been wearing – a green, tweedish costume enhancing her red hair. He gave her a job in the Bridlington repertory company where he himself was working, and asked her to marry him. As she was only 19, she declined.
She did, however, live with him – a fairly bold course even for thespians at that time. It was while they were together in the bath that he proposed for the umpteenth time, and on that occasion she accepted. Rix toured his production of John Chapman's Reluctant Heroes and took it to the Whitehall theatre – it was the first of the many farces there, which made his reputation, and ran from 1950 to 1954. Gray was in the same production, and a film version followed. They settled in the capital and started their family.
Gray was born in Inverness, Scotland, and went to school at St Margaret's, Hastings, and the Presentation Convent, Srinagar, in the Kashmir Valley, before doing her theatrical training at Rada. Her first professional appearance came in 1947, in the play Edward, My Son, at the Grand theatre, Leeds, which transferred to His Majesty's theatre in the West End the following month, so providing her London debut.
Her next stage role after Reluctant Heroes came in another farce, Wolf's Clothing (1959), at Wyndham's, and at the Garrick in 1967 she took part in her husband's farce season, appearing in Uproar in the House and Let Sleeping Wives Lie.
Four years later she was in a tour of four plays by the farceur Vernon Sylvaine, and in 1973 went to the O'Keefe theatre in Toronto, in a production of Move Over Mrs Markham. In 1980 she appeared at Joan Littlewood's Theatre Royal Stratford East in the melodrama The Streets of London, and in 1983 was in Charley's Aunt with Griff Rhys Jones at the Lyric, Hammersmith.
Gray made her first film in 1949, and later featured in Goodbye, Mr Chips (1969). Her many television roles included Lady Collingwood in Catweazle (1971), Chancellor Thalia in the Doctor Who story The Arc of Infinity (1973), and Phyllis Bristow in eight episodes of the second world war drama Tenko (1984).
In The Black Adder (1982), the first series in which Rowan Atkinson set about subverting British history, he played the mythical Edmund, Duke of Edinburgh, and Gray his mother, Queen Gertrude of Flanders, the consort of Brian Blessed as Richard IV. Her final TV appearance came in an episode of Victoria Wood's sitcom Dinnerladies (1998).
Shelley died in 2005. Gray is survived by her husband, two sons and a daughter.
• Elspet Gray (Elspeth Jean MacGregor-Gray), actor, born 12 April 1929; died 18 February 2013
