She was born Sheila O'Nions in in Birmingham, England, UK. During the Second World War, her family moved to Southport, Lancashire, where she met Des Walsh, son of Thomas Walsh, who had a jewelry store at 39 Chapel Street since 1926. In 1950, Sheila married Des Walsh, and they had two daughters, Fran Walsh and Tess Walsh. Sheila worked during years in her husband's familiar jewelry store, with her husband, her husband elder brother Gerard and his wife Dorothy.
In 1971, Sheila joined the Southport Writers' Circle, and years later, in 1986 was elected life president. In 1980 she became the vice-president of the Romantic Novelists' Association, and later elected Chairman (1985—1987)
Her debut novel, The Golden Songbird, won the Netta Muskett award for new writers from the Romantic Novelists' Association, and in 1984, her novel, A Highly Respectable Marriage won the Elizabeth Goudge award.
Sheila Walsh died at age 80.