Regardless of the cause ... Acting out in anger can get people into a world of hurt & trouble, therefore, I think the most important thing is to try to get them to see all the bad things that can befall them if they continue in it without even trying to get as much of a handle on it as they can.

To me nothing's worse than ending up homeless or in jail or prison because of mental health and addiction issues. Unfortunately - and sadly - society, law enforcement and the judicial system still have little to no empathy and/or compassion for those struggling with any of it.

So maybe if you could get her to understand how important it is to get help before all that happens then it will save her the heartache of all the added headaches and complications.

Of course, she may totally blow you off, and if that's the case, you've done all you can to try to help her, and the only thing left for you to do will be to let her learn her life story the hard way & without dragging you along for the ride.