She had established herself on the West End stage by the mid-1940s, after making her debut at the Comedy Theatre in 1944, as Effie in This Was A Woman. After Rattigan's While The Sun Shines (1945), playing the irrepressible good-time girl, Mabel Crumm, there followed a succession of leading roles, including Hetty, in Call Home The Heart (1947), and the formidably strait-laced Lady Orreyd, in HM Tennent's lavish 1950 revival of Pinero's society drama, The Second Mrs Tanqueray, about the dire consequences which could follow from a Victorian misalliance. It was a performance widely noticed for its aristocratic poise and sharp cutting edge.
National fame came in 1969, when Fraser was cast as Jean Ashton, the embattled matriarch of Granada Television's A Family At War, in which an ordinary northern family faced the perils and sacrifices of life in wartime Liverpool. She appeared in 45 of the serial's 52 episodes.
Eight years later, she was cast by George Lucas as Luke Skywalker's Aunt Beru in Star Wars. Although this was only a small character role, the fact that she had played a part in the most successful cinema attraction of its time resulted in an avalanche of global fan-mail - and her own internet website.
Fraser made a careful choice of her stage roles. In 1953, at the Arts Theatre, she played Cristine in a revival of Lennox Robinson's Drama At Inish, a delicate tragi-comedy of theatrical life in Northern Ireland, and, in the 1960s and 70s, she continued to appear in a range of plays by such notable dramatists as Harold Pinter (Flora, in A Slight Ache), Alan Ayckbourn (Delia, in A Bedroom Farce), Tennessee Williams and Edward Albee. In 1967, she gave a virulent and anguished account of Martha, in Who's Afraid Of Virginia Woolf, and, in 1973, a poignant study of Amanda Wingfield, the fluttery, clinging mother-figure in The Glass Menagerie.
Her last major stage appearance was in 1974, in David Hare's Knuckle, at the Royal Court, where her Mrs Dinning made a marked contribution to the play's edgy and disturbing effect.
Her television and film work was lively and varied, with two vivid flourishes marking her last appearances - as the demented old bag-lady who haunted the bar in the BBC version of Rodney Ackland's Absolute Hell, and as the paralysed, but wickedly communicative, stroke victim in Edith's Finger, which won the Welsh Bafta award for best short film in 1999.
Fraser's family was part of the City dynasty of jewellers Mappin and Webb. Her father was sent to Australia to found an outpost of the business, and, on his return to England, it was discovered that his daughter had contracted spinal tuberculosis, which, as a child, condemned her to lying flat in a specially elongated invalid carriage. She faced this adversity with courage, did well at St Christopher's school, Kingswood, and won a scholarship to a nearby drama school, attached to Croydon repertory theatre. Here, she made her first stage appearance, in 1938.
With her naturally inquiring mind, it was never likely that Fraser would be content to work simply as an actress. In the 1970s, by then in her 50s, she wrote two successful children's books, Captain Johnny and Princess Tai Lue, the tale of an exotic cat. But, as early as 1950, she had tried her hand as a playwright, collaborating on Always Afternoon, a languorous evocation of lotus-eating expatriates on the French riviera, which ran briefly at the Garrick Theatre.
In the 1980s, she became fascinated by the challenges of radio drama. As an actress, she had appeared in more than 500 radio plays, and, for a time, been a member of the BBC Repertory Company. Now, as a dramatist, she adapted Rose Macauley's The World My Wilderness and Rebecca West's The Salt Of The Earth for Radio 4. Her other play for radio was an original, The Maid's Room, a fascinating study of a servant-mistress relationship.
Fraser remained a strikingly pretty woman, whose appearance was marked with a characteristic expression in which humour and tenderness were equally mixed, and which reflected her warm and constant gift for friendship.
Shelagh Fraser, actress and writer, born November 25 1920; died August 29 2000
