I'm fairly sure that Peter Coss is the son of Hubertus Coss and Mary/Nancy Hardy. In the 1865 Seward, Schoharie New York State Census, Peter's mother is listed as Mary, aged 76, making her born about 1789. The 1850 census indicates Hubertus Coss's wife was borna 1790, as does the 1855 New York State Census. She is known as Mary/Maria/Nancy. It doesn't seem likely that Peter Coss's mother is a different person.

Kate