You still haven't said who OWNS the dog. If you want to keep the dog, and you have any kind of legal claim to it, then keep it. If you DON'T want the dog, then you can ask her what she wants you to do with it. Tell her you will take the dog wherever she says, provided they will take the dog.
And if she doesn't have anyone who will take the dog, then rescue is the best bet. If she cared so much about the dog (along with the rest of her life) she shouldn't have driven drunk (x3).