Me, too!! YAY!!!
I’ll recommend your mother try the Feliway, as I mentioned in this specific post.
Our kitty, Emma, came to us a complete basket case, terrified of everything, from being chased and beaten up and smacked around by 2 other cats, a dog and a new baby in her old home. She’d get petrified every time a stray or neighbor’s outdoor cat came in our yard, and would wail and holler and pee on the floor, poor thing. 
We installed a Feliway diffuser and she’s been like a different cat. And not one single incident of peeing outside her box.
I hope everything works out for everybody, and it’s great to know we have backups for both girls in case it doesn’t.
I used to keep a ball of “cat” yarn for my yarn baby…it was so ugly, that there was no way I would mistake it for something that I…you know…might want to make something with.