Sarah Margaret "Sally" Bell was born January 6, 1939, in Carlisle, England (near the Scottish border), the daughter of James and Sarah Price Wallace Bell. In the early 1940s, the Bells moved to Kingston-on-Thames, near London, but were soon evacuated back to Carlisle because of the war. By the time Sally was eight, the family had settled in Kingston, and she attended grammar school at New Malden.

In February 1952 James Bell emigrated to Canada, where he worked for a tool and die company in Toronto. He was shortly transferred to Buffalo, New York, and it was for this destination that Mrs. Bell sailed with her daughter and son in October aboard the Queen Elizabeth II. They docked in New York City, and traveled to Buffalo by train. In 1954, the Bells settled in the suburb of Hamburg.

Sally Bell graduated from Frontier Central High School in 1956. In the autumn of her senior year (1955), she attended the Billy Graham Crusade in Toronto, and there received Christ as her savior. Despite family opposition, she attended Buffalo Bible Institute, working nearly full time for the Buffalo Evening News to support herself. She completed the Institute's three-year course in 1960 and took a job with Morrison Steel Company in Buffalo. Through her church, she met Joe Coughlin of Christian Service Brigade, and in 1961 he persuaded Sally to move to Chicago where she was employed by CSB as a secretary. She moved in 1962 to Wheaton, Illinois, when CSB relocated there.

In Wheaton, Sally joined the Wheaton Bible Church, where she began to receive reminders of a commitment made several years earlier to become a missionary. An application to Sudan Interior Mission was met with advice to receive further training. But through Wheaton Bible Church she was put in touch with Abe Van der Puy of the radio mission HCJB in Quito, Ecuador, and she was soon hired to work with that mission. Sally left Wheaton for candidates' school in June 1964, and went from there to Costa Rica in August for eight months of language school. She arrived in Quito in April 1965. At HCJB she worked as a secretary successively in the Evangelism and Television departments before moving to Field Services, involved with personnel.

She had several short furloughs, the longest of which was from April to November 1969. She was home briefly in 1970-1971 at the time of her mother's death. In 1976, Sally resigned from HCJB and returned to the States for medical reasons. She was offered and accepted a position as secretary of Wheaton Bible Church. A succession of operations from 1976 to 1980 culminated in August 1980 with a stroke, which deprived her of memory, speech, and movement in her right side. Through therapy and over time, all were recovered. As of 1982, Sally was preparing to return to Quito in January 1983.