His sister has moved with their mother and won't tell him the address. We are so frustrated. My husband's sister decided to move in with their elderly mother who has progressive dementia. At first we thought it was a good idea but now she has moved with their mom and won't tell my husband where they have moved to. We know she has convinced my mother in law to add the sister's name to her bank account and we believe that she is helping herself to the life savings the mom has spent her whole life accumulating. My husband was the POA but the sister convinced the mom to replace him with you know who. Isn't it tragic that we are talking about family members that commit this kind of treachery.
Sil gave my husband a bogus phone number. It's like she is trying to erase him from Mil memory. He only wants to talk to his mom. When he has tried to set up a time to visit his mom is conveniently not home.
My heart aches for him. My family is loving and supportive but he has always had a close relationship with his mom.
If the only thing you want is the address, there are search engines online for that sort of thing that will charge you. With a move that fresh the results might be iffy. I like spokeo best and it's free to begin with. Heck they are down right scarey for all they know. You can also hire a private detective if you are truly afraid for your mother's health and life, he or she can get all kinds of stuff on your SiL if there is anything to be had.
I wish you all the best.