Mary F. Purple (b. Foster) (c. 1846-1898) was born in Portland, Connecticut, and died in Chicago, Illinois. She married William B. Purple in Chicago in 1887. Purple was a student of Mary Baker Eddy, completing her Normal class in October 1887. Purple taught Christian Science Sunday School for many years. Along with fellow Eddy students Emma L. Baird and Ruth B. Ewing, Purple wished to start a Christian Science Institute in Chicago. Although they had Eddy's blessing, the project did not come to fruition. The Purples joined The First Church of Christ, Scientist, in Boston, Massachusetts, on March 31, 1894 and were also members and officers of First Church of Christ, Scientist, Chicago, of which they helped establish. They were listed together in the directory of The Christian Science Journal as Christian Science practitioners, with Mary also advertising as a teacher, in Chicago from 1895 until her passing. William continued to advertise and work as a practitioner until he passed away in 1919.

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