Thank you so much. No, I doubt anybody has bothered to make sure she was declared mentally incompetent. If it's necessary I expect the adult grandchildren will have to try and find out from her doctor but if they don't have executor rights to her estate, I'm guessing they wouldn't be able to get it.
Plus they all live in Alberta and wouldn't know how to begin or who to begin with since the executor is clearly trying to secure the estate for themselves.
I'll send my son an email and ask about the probate and such but I doubt he has a clue.
Thank you again :)