I'm under no illusion that we could have stopped or prevented the mess we are in now.
SIL was going to get the Power of Attorney with or without us. SIL was going to rent the big house designed by the mafia don, using Mom's money with or without us. And she was going to "combine" her income and Mom's income regardless of if we said anything about it. I put "combine" in quotes because when I looked at the bank statements I saw very little of anything they may have come from unemployed unmarried SIL.
Supposedly SIL as handling the affairs of Mom, taking her out of the adult care facility to a SFH in the burbs that she rented with Mom's money. SIL put her name on Mom's accounts, and that's where the problem started.
My DH and my SIL both suck at money.
If SIL actually had an income, she should have had a separate account for her own expenses. Then maybe she wouldn't have attracted the attention of Adult Protective Services. So when SIL decided to take a vacation to a vacation spot, it wouldn't look like she was stealing money if it came from her own account. But because she used Mom's account it looked like she was stealing money.
DH and I are keeping our accounts separate from Mom's.
It helps that we are both year round employed people who have been working full time at places we've been at for more than a decade, so we don't need to use Mom's money except to care for Mom. We will however need to be reimbursed for the trip DH took out to the West Coast and for the $5000 we took out of our emergency savings for the lawyer. The $500 for the Medicare that we paid from our funds, we'll eat that.
DH name is on the new account to serve Mom. He will not be funding his trips to Panda Express from her account, because trips to Panda Express do not help Mom. He has paid rent money from Mom's account, because it went to pay for Mom's rent. In the place where she is currently living. It does not pay for our mortgage.
Simple lesson for honest caretakers, keep your spending and the person you are caring for's spending separate. Otherwise, it looks like you are stealing.