My great-great-grandparents, Claude Gelinas Lacourse and Flavie Bonin, married in Quebec in 1838 and ten years later migrated "to Ontario" with the first two or three of their 11 children. Last week I acquired the names of the 7 children I had not been able to identify, and one of them is Clemence. Unfortunately there is no indication of when she was born, and I haven't yet had time to check any further (now that I have names, at least). But from reading through the posts here, I really think there's a good possibility that she is the Clemence Gelinas you're looking for, and that she married a Bessette and died after her only child was born.
Claude and Flavie's family was particularly difficult to track because they didn't migrate from Quebec to Huron County (Stanley township), Ontario and stay put. A child was apparently born in Ontario, then two more were born around Port Huron, Michigan and four were born I know not where. With this additional information about the Bessette connection, I'll check further and let you know if I learn anything conclusive.
Any help would be most welcome.