I think they have tried to get some sort of court order in the past. The extreme would be to get her involuntarily sectioned, but that takes an awful lot.
I don't know why she has taken the path she has taken, but I hope she changes things soon, or she will die. There is always a reason for such self destruction, so I always think that people like her are worthy of pity, even if we can't understand why this has happened.
Vicky