That is very curious and worth looking into. I checked for a death registration and the only one I could find was Jane M Reid died September quarter aged 78 which doesn't fit.
1948 was before her husband's death in 1952 but maybe she left him and that is why his sister was the informant and not her.
The Blair alternative surname is also curious as her maiden name was Ross but her sister, Grace's married name was Blair. She could have changed her name. I have come across this before and I suppose anything is possible.
The beneficiary's name Elizabeth Gould Purvis doesn't mean anything to us either.