Probably Mary Louisa Sanger (1813-1877), a convert of the Church of Jesus Christ of Latter Day Saints in September 1843. She initially supported the claims of James Jesse Strang, but broke with him by 1849.
Letter ostensibly written by Joseph Smith to James Jesse Strang from Nauvoo, Illinois, and published by Strang in the Voree Herald, January 1846, as well as in his The Diamond: Being the Law of Prophetic Succession and a Defense of the Calling of James J. Strang as Successor to Joseph Smith (Voree, Wisconsin, 1848) and The Prophetic Controversy: A Letter from James Strang to Mrs. Corey (St. James, Michigan, 1854). Accompanied by an unsigned note from a child of Strang.
Photostat copy.