Hi, I am not a relative but some suggestions to try to find them:
Do you know where in Canada they settled?
Unfortunately each province does something different. BC (British Columbia) and Ontario are the best as they both have indexes available online/ fairly easily.
BC is online and searchable at
http://search.bcarchives.gov.bc.ca/sn-221C10/gbsearch/ . You can order electronically (their way to make money ) but if you are local (or you find someone local) you can get cheaper copies by going to the local library (there are several that hold copies)
I looked for Catherine Norris (it is indexed under married name and there was one Catherine E that died in 1975 but she was only 58 at the time so that doesn't look like it could be her.
I then looked for a Margaret Anne Ross and found one who died in Vancouver in 1970 at age 85 (which would be the right age)
Ontario has put a lot of records on Ancestry lately so if you can get to Ancestry Library Edition, you can look at those.
I don't know about all provinces but Ontario often does not have who informed on the death record and sometimes has less detail. BC records on contrast are fairly detailed with how long they lived in the city, province, and Canada. As well as parent's names, birth date, and informant (which is usually a relative) If the informant knew the info, it is quite useful especially to find children who are reporting the parent's death.
Good luck in your search, I hope you find someone.
Mary
HH