Hi,
I don't think Margaret was a young widow.
On the 1928 marriage of Charles and Margaret, Charles gives his parents as Samuel Doyle and Sadie Devison.
I think this is the family in 1921 Census
Glace Bay, Cape Breton, Nova Scotia,
703 SterlingSamuel, Sadie (Sarah), children John, Daniel, Charles, James, Samuel, Joseph, Miles, and Katie.
http://central.bac-lac.gc.ca/.item/?app=Census1921&op=img&id=e002904485There is a death of Sarah Doyle in 1957 Glace Bay, widow of Samuel Doyle
Son Charles is the informant, and his address is
703 Sterling, Glace Bay.
https://www.novascotiagenealogy.com/ItemView.aspx?ImageFile=1957-5110&Event=death&ID=3905631957 Canada Voters List, Glace Bay,
703 SterlingDoyle, Eunice, clerk
Doyle, Miles, miner
Doyle, Mrs. Miles
Doyle, Mrs. Sarah, widow
Doyle, Charles, electrician
The last sighting for Charles, 1968 Canada Voters List, Glace Bay,
703 SterlingDoyle, Miles, miner
Doyle, Mrs. Miles
Doyle, Charles, pensioner
Gotta love these families who remain at the same address.

DB