Also known as Jackie Forster, her father was a colonel in the Army Medical Corps, and she spent her early years in India. She went to school in Britain, boarding at Wycombe Abbey and then St Leonard's School in Fife.
After school she joined the Wilson Barrett repertory company in Edinburgh. She then moved to London's Arts Theatre Club in the late 1940s. This was followed by a period in film.
During the 1950s and 1960s she was a television presenter on a wide variety of magazine and travel programmes. In the 1960s she worked for Border Television.
In 1957 she was on a lecture tour in Savannah, Georgia, when she had her first lesbian affair. Despite this she married the author Peter Forster in 1958, but the marriage was over within two years as she accepted her true sexual identity. They divorced in 1962. In 1969 she came out publicly as a lesbian and held forth at Speakers' Corner at Hyde Park, London.
After coming out Jackie Forster worked with groups like Lesbian Archives, the Minorities Research Group, and gay medical and social workers' organisations. She pioneered work on artificial insemination by donor for lesbians wishing to become mothers. In the 1970s she worked on the lesbian magazine Arena 3.
In 1972 she was one of the founders of Sappho which was Britain's longest-running lesbian publication. Sappho organised meetings in a Chepstow public house with speakers including Anna Raeburn, Mikki Doyle from the Morning Star, Maureen Duffy who read her poetry, and the barrister Elizabeth Woodcraft who spoke on the rights of lesbian mothers.
Sappho ceased publication in 1981 and Jackie Forster joined the Greater London Council's Women's Committee and became a director of the London Women's Centre. She became a member of the board of the Lesbian Archive and was an active member until her death. In 1969 she joined the Campaign for Homosexual Equality (CHE) and came to serve on its Executive Committee. She was a founder member of the Gay Liberation Front (GLF) and she was on the first Gay Pride march in August 1971, and led sit-ins at anti-gay pubs and radio stations.
She was the co-scriptwriter of the 60-minute television programme about London CHE groups, Speak for Yourself, which was shown by London Weekend Television on the evening of 21st. July 1974 as part of Britain's first ever 'access television' series. As well as presenting a number of documentary programmes she also acted in radio and television plays and in films.
In 1993 she was diagnosed with breast cancer but recovered. She went on to agitate on behalf of breast cancer awareness. She died at the age 71 of emphysema, and was survived by her partner Lace.