The 1860 Federal Census for "Henr Heinze", my GG-Grandfather, shows a Cath. Fiegge, age 58, living at their address in St. Louis. There is a note next to the name which I've never been able to figure out. Could this be the Katherine that married Christian in Germany? My Heinze ancestors immigrated to St. Louis in 1850 +/- 2 yrs, from Hessen Darmstadt.
If you'd like to check out the census, it is page 108 of the 1860 Missouri, St.Louis (independent city), St. Louis Ward 2 census. Or search for "Henr Heinze"
Let me know if you think it is a match. Reply here. I have alerts set.