A history of Charles Jameson by D. Allen Jameson, a grt-grandson, claims that Mary Ann was a daughter of Charles Jameson and Mary Ann Hedrick, and the divorced wife of James R. Hirons. After the divorce she married her brother-in-law, Jehu Blackburn who had already married two of her sisters, Julia Ann and Susannah. Charles and Mary Ann did have a daughter Mary Ann who married James Hirons and was divorced from him in 1848 in Salt Lake. The records of the Endowment House and the 1860 census for Utah make it clear that the Mary Ann Hirons who married Jehu Blackburn was not Mary Ann Jameson Hirons. The End. House records give Mary Ann Blackburn’s parents as Henry and Sarh Hirons, and her birth place as Caldwell, Ray, Missouri. The 1860 census has her age as 25. Mary Ann Jameson Hirons would have been 35 by that time and she was born in Ohio. There definitely seem to be two women, one Mary Ann Hirons Blackburn and the other Mary Ann Jameson Hirons. There is some indication that Mary Ann Jameson Hirons died before 1850.
Henry Hirons is native to Germany according to the census. His name is also spelled Irons. The Hirous would be a misreading on Hirons, substituting a “u” for the “n”, this is a common mistake in reading handwriting.
Her husband was Jehu, the John came from misreading sloppy hand writing. My Grandfather was a grandson of him and a son of Jehu Jr.
I hope this helps you. I am a desc. of Jehu and his first wife, Julia Ann.