Canada East refers to Quebec, also called Lower Canada and French Canada and in Census comes up as Canada Fr. In most cases this is not the nationality but the locality. If you haven't already done so, I recommend starting with Loiselle's Marriage Index at an Family History Library. She was certainly old enough to have married before 1846. Do you have the years of birth and are the oldest children born in Canada? Do you have a wife for Isaac? His marriage if in Quebec could be your breakthrough. Family History Library also can order in Vital Records Indexes for Wisconsin.