Hi Jean Marie, Thank you for looking into this as well. I believe the couple I am looking for were actually married in England before coming to Canada. From what I can tell, they were only in Montreal for a short time before moving out to Middlesex county in Ontario. Their son William was born in Montreal according to his marriage certificate. I found a few Robert Taylors listed in the Montreal city directory around 1842 but they don't show spouses or children. The 1851 census shows them in Ontario. They had a daughter Margret before coming to Canada as she is listed as being born in England. I think this is the correct family I am looking for as the ages and time frames seem to add up.
Thanks again for all your help. It is appreciated.