The census appears to be her, as her second husband had children named Mark and John. I've seen her birth year listed from 1806-1813, but never a 1817, but I suppose it's possible. I found a death record for her at Ontario, Canada, Deaths and Deaths Overseas 1869-1947, but it doesn't list her parents. It also lists her as married, but her husband Alexander died 11 years earlier. The search continues.