1911 census, Mary Smith c 1866 is a visitor aged 45 with 2 sons (as Below) in the household of an Albert Smith aged 49 and his wife in Stretford, Lancs. (Possibly Thomas Smith's brother, both born same place)
Free search of 1921 census shows Thomas and Mary together
Mary
Smith
1866
Accrington, Lancashire, England
Astley
Leigh
Lancashire
Thomas
Smith
1860
Astley, Lancashire, England
Astley
Leigh
Lancashire
SMITH, THOMAS mmn CHADWICK
GRO Reference: 1902 J Quarter in LEIGH Volume 08C Page 302
SMITH, JOHN (Jack in 1911) mmn CHADWICK
GRO Reference: 1910 J Quarter in LEIGH Volume 08C Page 285
John