OK, I think I've sussed out the Spence branch.
Sarah G Baker's maiden name was Spence. Her father was William Spence b. abt. 1801 Ireland, her mother was Martha Spence (nee ?) b. abt. 1802 Ireland. Ann(e) Spence was probably William's sister.
1851 Census, Nelson, Halton, Canada West.
William Spence, b. Ireland, farmer. Age next birthday 51 (he is listed on separate page to rest of family, not in sequence ??)
Martha Spence, b. Ireland, Housekeeper. Age next birthday 50
William Spence. b. Canada, Labourer, Age n.b. 17
Sarah Georgina Spence, Age n.b. 14
Robert Spence, b. Canada, Age n.b. 10
Anne Spence b. Ireland, Age n.b. 60
1861 Census, Nelson, Halton, Canada West.
William Spence, b. Ireland, farmer, married. Age next birthday 60
Martha Spence, b. Ireland, married. Age n.b. 59
Anne Spence b. Ireland, single. Age n.b. 71
William Spence jnr. b. Canada, Labourer, single, Age n.b. 26
Robert Spence, b. Canada, Labourer, single, Age n.b. 19
I have found a death record for a William Spence who sadly died Christmas day 1894 in Huron, Ontario, age 89 b. Fermanagh Ireland, a bit difficult to read but I'll have another look tomorrow.
Jool