Her screen debut came in 1944 with the small role of Millie in the film Welcome, Mr Washington (1944) and this was followed by a small supporting role as a girl in a guard’s van in the wartime drama I Live in Grosvenor Square (1945). More substantial, and her television debut, was the character Leila Arden in a BBC television adaptation of the Patrick Hamilton play Rope (5th January 1947). Just over a year later Alfred Hitchcock would make his own film version of the play starring James Stewart. Further film appearances for 1947 included an uncredited role in Meet Me at Dawn (1947) and the period drama The Master of Bankdam (1947) in the larger role of Alice France (credited as Shelagh Frazer).
During summer 1952 Fraser played Lady Orreyed in The Second Mrs Tanqueray in a provincial theatre tour and, later, at the Haymarket Theatre in London’s West End. She would later reprise this role in the 1952 film version. Later in the year she co-wrote, along with Victor Becker, the play Home or Away as well as starring in the presented production at the New Theatre, Bromley. During August and September 1952 she was a cast member of the comedy The Wedding Ring. Back at the BBC she was cast as Kitty in the one-off drama Two For A Pair (9th October 1951) and appeared in 'Coming Out Party' (8th December 1951), the opening episode of the second season of The Inch Man, a forgotten BBC drama series featuring the adventures of a house detective in a London hotel. This was followed by the BBC Sunday Night Theatre production of 'No Smoking'” (16th March 1952) playing Sylvia. Her 1952 cinema roles included Myra Lorne in Salute the Toff AKA Brighthaven Express (1952) and the aforementioned The Second Mrs Tanqueray (1952). On television she appeared in the single BBC drama If This Be Error (11th November 1952) with a cast that also included Peter Cushing and Dandy Nichols.
Theatre work, such as portraying Hermione in The Private Life of Helen in a touring presentation during April / May 1953 and Drama at Inish during October / November 1953, occupied her time and she made no film or television appearances during this period. Along with Billy Thatcher she wrote Tai Lu Flies Abroad, which detailed the adventures of a magic Siamese cat, for Hullo There!, a weekly radio magazine programme for young listeners. Dorothy Gordon narrated the cat’s adventures and they proved so popular that the adventures also featured in their own children’s television series broadcast by the BBC between 1952 and 1954. Fraser, Thatcher and Dorothy Gordon narrated the tales with illustrations by Janet and Anne Grahame-Johnstone and musical accompaniment by Donald Swann. A series of books based on the feline’s adventures were published from 1955 onwards with Fraser and Thatcher adapting their own tales. Fraser returned to television in 1955 with the role of Emma Horton in the 'Fabian of Scotland Yard' episode The Lover’s Knot (27th April 1955) and a headlining role as Mary Kent opposite Kenneth More, as her husband Tony, in the comedy film Raising A Riot (1955).
The year of 1962 bought two television roles – Mary Duckworth in the Z Cars story 'Person Unknown' (14th November 1962) and Ruth Kindred in the ITV Play of the Week episode 'A Matter of Principle' (11th September 1962). The following saw year a pair of ITV Play of the Week productions featuring Fraser. First was the original screenplay 'Girl with a Difference' (14th May 1963) followed by the John Bowen scripted 'The Truth about Alan' (4th June 1963) which also featured Anthony Bate who would later appear in 'During Barty’s Party'. Towards the end of the year Fraser made her first guest appearance in an episode of Dr Finlay’s Casebook when she took the role of Jean Docherty in 'Odds on Johnny' (1st November 1963). The year ended with Fraser appearing as Claire Jusserand in the Maigret story 'Maigret’s Little Joke' (24th December 1963).
A Man of Our Times was a George Cole starring series in which he played a harassed man who is dismissed from his managerial job and finds himself in marital turmoil at the same time. Fraser popped up in one episode of the series – 'Never Mind How We Got Here, Where Are We?' (14th March 1968) - in the role of Mrs Manson. The cast also included Bruce Robinson in the role of her son Rex. Robinson later found a cult following as the writer and director of the sublime Withnail And I (1987). On the big screen Fraser could be seen in the movie version of Till Death Do Us Part (1968). The following year saw Fraser make a couple of TV appearances; Daphne in the ITV Sunday Night Theatre production 'The Piano Tuner' (8th March 1969), as Mrs Evesby in the First Lady episode 'All In A Good Cause' (19th June 1969) and for the BBC’s Wednesday Play slot she played Mrs Grayson in 'The Last Train Through Harecastle Tunnel' (1st October 1969). The majority of her onscreen appearances for the year were in cinema. She could be seen as Mrs Thatcher in the low budget British science fiction film The Bodysnatchers (1969), had an uncredited role as Miss Gurnsey in Waris Hussein’s drama A Touch of Love (1969) and another small role in the comedy Staircase (1969). She also had another role as a mother, this time to Judy Geeson’s character, in the film Two Gentlemen Sharing (1969).
Between 1970 and 1971 she would appear in the TV drama A Family at War in another matriarchal role as Jean Ashton. This role not only made her a recognisable face with the general public, but also kept her in regular employment which curtailed her chance to appear in other programmes. She did find time to make one guest appearance in one other series during this period with the character Joan Prentice in the Doomwatch episode 'The Islanders' (4th January 1971). The following year she was cast in the Doomwatch (1972) movie playing a different character, Betty Straker, in a poorly developed adaptation of the television episode. Following her exit from A Family at War Fraser guest starred in the Follyfoot episode 'Out-of-the-Blue Horse' (13th August 1972) in the role of Vera Berwick.
In the year prior to her role in Beasts Fraser played Lady Bassinger in the Wodehouse Playhouse episode 'Unpleasantness at Bludleigh Court' (14th May 1975) and Mrs Heath in the Armchair Cinema production 'In Sickness and In Health' (21st May 1975). Her role as Dorothy Pummery, the wife of TP Mckenna’s character Dick, in 'Baby' was next. Her final TV role was in an episode of the children’s horror anthology series Shadows, 'Brief Encounter' (18th August 1976), written by Susan Cooper.
Her first screen role of the 1980s was as Diana Price in the BBC drama The Old Men at the Zoo (15th September – 13th October 1983). From now on her screen roles became sporadic and she was not seen again until a tiny role as a CND supporter in the BBC Screen Two drama 'Frankie and Johnnie' (2nd February 1986) directed by Martin Campbell who had overseen her appearances in The Professionals. Her final film role came with another “cough and spit” role as a Women’s Volunteer Service member in John Boorman’s Hope and Glory (1987). She then made an appearance as a lost shopper in the comedy short film Work Experience (1989) which also starred Lenny Henry and Kathy Burke
Redundancy drama 'The Merrihill Millionaires' (29th September 1993) was a Screenplay production. Fraser featured in the cast as Mrs Wilson. 'House Calls' (16th February 1997) was an instalment of the detective series A Touch of Frost. Fraser appeared in the role of Mrs Hinckley. Following this she could be seen as Sarah Thorpe in the Heartbeat episode 'Local Knowledge' (25th January 1998). Her penultimate screen role was as Edith in the short film Edith’s Finger (2000). Edith is an elderly lady who has suffered a stroke and is only able to communicate by tapping her finger. The production won the Welsh Bafta award for best short film.
Fraser’s final screen role was as Jane Rochelle in the Midsommer Murders episode 'Judgement Day' (29th January 2000). Her final role was made even more notable by the fact that the episode marked Fraser appearing alongside fellow 'Baby' cast member Jane Wymark, who played the regular role of Joyce Barnaby.
During the 1980s Fraser turned her attention to writing radio dramas, having appeared in hundreds of radio plays during her acting career as a member of the BBC Repertory Company from 1942 onwards. For Radio 4 she adapted The World My Wilderness by Rose Macauley and The Salt of the Earth by Rebecca West. She also wrote an original radio play, The Maid’s Room. Fraser passed away on 29th August, 2000 in London at the age of 79. Her obituary in the newspaper The Guardian noted that “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.”