There is a Thomas and Mary Marshall (ages 29 and 32 respectively) in the 1881 census for Walkerton, Ontario. If this is the right couple, they also had a son Ralph (born about 1877), and a son William (born about 1879).
In the 1906 census, they are in Moosomin, Saskatchewan.
In the 1911 census for Moose Jaw, Saskatchewan, Thomas, his wife Mary, nad daughter Helen M. are living on Alder Avenue. He is listed as a salesman.
In the 1916 census, the 3 of them are living . He is listed as a salesman.