If in fact her BF is in reality a Loan Shark she could get the police to help her for a bit of information that she may have garnered while living with him.
Just a thought. Of course, it would also mean that she would be ready to find recovery, and in that instant the DA would more than help her.
Other than that, she's going to have to decide. It is her choices.
Just stay strong mom, you may actually be seeing her getting closer to her own bottom.
Remember we are walking with you in spirit.
Love and hugs,