www.deathindexes.com/canada.htmlunder marriages she is listed as
May when she married Donald McLeod, 1919/09/24, Vancouver
Mae Christie when she married Gordon Walker Harper, 1935/09/19, Vancouver
marriage information is only available until 1935 on this site
death
Gordon Walker Harper, 1938/07/17 Vancouver, age 44
He is buried in Mountain View Cemetery, Section HORNE2/#/15/042/0005
I don't see her buried with him so it is possible that she either remarried or didn't die in BC.
Someone may have access to street directories or old phone books that may list her in them. You may be able to get an obituary from old newspapers for Gordon that may list other family members that could help in your search. The public library in Vancouver may be able to help with old newspapers searches and they may have old telephone books as well. The phone books may give you an idea of when she may have remarried or died if she is in early books and then not in later ones.