Newfoundland was a British colony until 1949 when it joined Canada. Her birth certificate will not be available to you because it was way too recent.
Her obituary in the Toronto Star gives no clues as to the names of her parents or whether there were any siblings. George seemed to be from Toronto, so they were likely married there. Do you have the date of their marriage and where? If in Ontario, you could obtain a copy of the marriage record (with proof of her death) from:https://www.orgforms.gov.on.ca/eForms/start.do
This should at least name her parents.