The 1871 Canadian Census shows John and Margaret Brine (sic) in Whitchurch Township with sons William John, aged 7, and Robert, aged 5 which gives a slightly different year of birth for him. If John remarried in 1872, it could only have been because of Margaret's death -- there being no divorce available. Also, the 1871 census indicates that Margaret was born in Ireland, not Scotland. The marriage indicates the same.
In the 1861 census, Margaret is living in the home of John Gould in Whitchurch Township, born in Ireland.