Eliza E. Cartwright says that Solomon Spaulding's daughter told her that one his characters was called "Mormon."
Eliza E. Cartwright, "Knew Daughter of Solomon Spaulding," Salt Lake Tribune 76, no. 50 (December 3, 1907): 8
I had the honor of being for several years most intimately acquainted with Solomon Spalding's daughter. Mrs. McKinstry. I do not know what light my statements may throw on the authenticity of the Spalding manuscript, but I would beg leave to state that in the year 1881, at which time Mrs. McKinstry related to me the story of the so-called "Book of Mormon," she was in full and perfect possession of her faculties, the memory was unusually good, and she could recall events of years long passed and of dates when the events occurred, with perfect accuracy.
She told me that her father had a habit of reading at night to the assembled family what he had written during the day. She remembered very distinctly that a character in Spalding's romance was called "Mormon." This romance she declared to me was stolen from the family, and that the thief (whom, out of regard for our Mormon friends shall be nameless), altered and amplified her father's manuscript, leaving, she asserted, enough of the minister's work to be perfectly recognizable by the family. Mrs. McKinstry was a woman of high moral character, and her testimony I would regard, from my knowledge of her, derived from years of intimacy, as unusually reliable.
ELIZA E. CARTWRIGHT
Ogden, Utah Dec. 1, 1907.