Sarah Ellen Welch was the daughter of Boucher Welch, a farmer, grazier and chemist, and his first wife Emily. The Welch family emigrated from England in 1853 on the Belmont. Early in 1854 they went to live in Hindmarsh Valley, settling in Port Elliot. Sarah Welch's mother died, apparently after a long illness, three months after giving birth to Sarah's brother Hamilton in 1856. Sarah would have been about five years old at the time, with other brothers aged about seven and three.

In 1959 her father married widow Mrs Sarah Storer, some nine years his senior. Sarah (the daughter) lived all her life in the Hindmarsh Valley, except for a visit to England. She was an active worker in St Jude's Church, Port Elliot, a member of the choir and an associate (as a single woman) of the Mothers' Union. When she died at the age of 62, her obituary in the Chronicle described her as "a universal favourite in the district" and added that "every philanthropic movement received her most active support, and she will be much missed in the locality."

Sarah Welch wrote religious and moral fiction and published a number of short stories and serialised novellas in the Australian Journal under the pseudonym Europa. Because her work appeared under the "Answers to Correspondence" column of the Journal it is unlikely that Welch was paid for her submissions (Toni Johnson-Woods, Index to Serials p.102).