I figured out that Samuel's daughter, whose home he died at in 1932, was Edna Mary, married to Roland James Elliott. Edna Mary died Jan 11, 1994 in Ontario, Canada.
Alexander James Duncan died Apr 18, 1916 in Toronto, Ontario. Perhaps his obit would mention his half-brother Thomas Duncan. Alexander married Jane Barry Feb 18, 1862 in the Presbyterian Church in Ottawa. Jane died May 21, 1915 in Ottawa.
Peggy