Looking for Parentage of George W Simmons and OR His Wife Marie J Bowen of Canada

I am looking for the parents of either or both of George W Simmons, born about 1808 in Canada who most likely died before 1860 in Canada. His wife was Marie J Bowen, was born approximately in 1812 in Burford, Brant County, Ontario and died August 16th 1885 in Grand Rapids, Michigan. They had 4 children that I could find (one of which my husband's ancestor) named Charlotte, Sarah, George & Edward. They were all born in Canada but moved to Michigan in 1860 or so. I cannot find a marriage certificate for the couple or anything about their parents. I've been looking for YEARS!!! HELP!!!!