There is nothing that any of us can say that will help you ease the pain of knowing that you a going to lose your mother. She sounds like an absolutely wonderful women and consider yourself blessed for the time you had with her and everything you shared together.
I understand the decision of whatever is comfortable for her and please have a peace of mind in knowing that she chose the final steps in her life long journey.
Though non of us know each other, we're still a steem family and your steem family loves you.