Born ‎29 Dec 1833 Tipperary, Ireland, died ‎22 Jan 1922 Sedan, Pope County, Minnesota‎, age 88 years
William and Mary are listed in the 1880 census without children, but have a 13 year old farm laborer living with them. There is a note next to William that said "lost leg in army". In the 1900 census of Raymond Township, Stearns County, Minnesota, William Douglas's 15-year-old nephew Charles is living with them, as is Mat Morris, Mary's nephew (son of John Morris and Bridget Tracy, born 1880) . William is listed as being born "at sea". The census states that William and Mary had two children, neither of whom is now living. In the 1910 census they are living in Sedan, Pope County. It indicates they didn't have any children.

Born ‎Oct 1842 Wakefield Township, Outaouais, Quebec, Canada, died ‎after 1922 Pope County, Minnesota‎, age at least 80 years
The 1851 census of Canada shows that Mary was 9 years old, making her born in approximately 1842. Catherine is 7 in that census, so Mary is two years older.