Hello BoxTurtle: Thank you for bringing your concern here to PC.
Since this is your first post here on PC, welcome to Psych Central.
I'm sorry you are having such a difficult time with your family member. I'm not a mental health professional. So I can't offer you anything in the way of a diagnosis or authoritative advice with regard to your family member. (Perhaps other PC members will have some suggestions they can offer.)
You asked what you can do to get your family member to stop doing what she's doing. The only things that occur to me are, first, get a different phone number & make sure you block hers. Cut off any-&-all contact of any kind. And second I guess if I had had personal belongings destroyed by someone, I would call the police & file a complaint. Perhaps one of the reasons your family member is treating you the way she is, is because she feels safe doing so. She's learned from experience she can do whatever she wants to you & you'll take it. So you've become her personal whipping post, so to speak.
You mentioned your family member refuses to seek treatment. Unfortunately, as our host Dr. John Grohol, Psy. D. has written: "Denial is a Powerful Impediment to Treatment". Here's a link to that article from Psych Central's archives:
Denial is a Powerful Impediment to Treatment
I, of course, don't know what the laws are where you live. But, typically, the only way a person can be forced into treatment is if it can be shown they are a danger to themselves or others. So it may well be the only way you're going to be able to impact this situation is to begin reaching out the authorities where you live (the police, governmental social services agencies, etc.) in an effort to force your family member into treatment. Beyond that, finding a new job & moving somewhere far away from this person may be the best you can do. At least these are my non-professional thoughts with regard to your predicament. I'm afraid there simply aren't an simple solutions. At least none I would be aware of.
I hope you find PC to be of benefit.
P.S. Toward the end of your post, you mentioned thinking your family member may have Antisocial Personality Disorder. I do think it is always dangerous for those of us who are not trained mental health professionals to try to come up with a diagnosis for someone they're concerned about. However, with that thought in mind here's a link to an article, also from PC's archives, on how to cope with a sociopath:
Coping with Sociopaths (Antisocial Personality Disorder)