Thank you Judy for taking the time to do that. I imagine the summary of US Census information will be of interest and use to more that just me.

Children of John & Mary Jane as passed to me (no location or sources given)

John 1842-1911 m. CF Morris 1865
Richard 1844-1853 (so not on 1860 census)
Mary Eliza 1845-1888, m. H. Smith 1867
Thomas 1849-1865 (“Civil War casualty”)
William Malay 1851-1913 m. Mat. Bevelhymer 1875
Frances Emma 1853-“before 1882” m. WE Chippy 1873
Henry Harris Jan 1855-1893 m. Mary Bevelhymer 1881
Margaret Jane 1857?-“after 1882” m. ? Cook (informant has Scott Cook, but 1880 census has a plausible Nathaniel)
Charles 1859-1861
Elfrida 1861- 1863

I will have to find out if there is any family tradition of Mary J. remarrying. IGI didn’t throw anything up. Son Henry H. could certainly be child no.7 as given to me. Is his wife named as Mary, by any chance? If you have the time and inclination, I would love to see the detail of that 1900 entry. John & Mary J. seem to have had 10 children, not nine, but there would be 3 surviving as stated if Margaret got to 1900. Perhaps Mary wasn’t counting the one she was living with!

Thank you once again for all your help. It is much appreciated.