The problem is that she won’t change until she wants to. My husbands sibiling struggles with severe addiction. The family has funded multiple inpatient and outpatient rehab stays, hospital stays, etc. it works for a while, until the person wants to use again and then they do.
It’s unfortunate, but the long term sobriety rate is pretty low. Relapses happen quite often. Forcing her into rehab might work, but she might just ‘tell them what they want to hear’ so she’s released. She’ll be sober because they’ll detox her, but she can go right back to drinking if she’s not committed to being clean.
The problem with removing her funding is the deep desire she has for alcohol. Cutting her off won’t force her to stop drinking, as you know. It will just mean she’s not drinking on her dad’s dime. Unfortunately, addicts will go to extreme measures to get what they need. It’s possible your fiancé thinks it’s easier to find her drinking than think of her living on the street, doing whatever she has to do in order to get booze. She might move in with some other addict friends she uses with, which will probably propel her addiction further along.
I am not saying he’s right for funding her life, but just presenting the alternative, and what is likely to happen if he stops paying her rent or giving her money.
if you push him to cut her off, be prepared that he could resent and blame you when something bad happens to her. It’s not your fault of course, and it’s not right, but you have to acknowledge what can happen.
There is a reason addiction wrecks families- not just the addict’s relationships. It’s easier to be the first or second person to disengage with her. It’s much much harder when he is the ‘last one standing’. If he cuts her off, it’s pretty clear what will happen. Which I am sure makes it that much more difficult for him.
My advice is to keep supporting the idea of rehab, and disengage to other conversations. Stay out of it as much as possible, because being involved will only drag you down, too. If he wants to give her $500 a month, fine. That’s his ‘going out with the boys’ money for the month or whatever other sacrifice makes sense. Your only role is ‘well, I think that rehab place in westville still has openings’.