Physical & Emotional Abuse Support Group
Abuse is a general term for the treatment of someone that causes some kind of harm (to the abused person, to the abusers themselves, or to someone else) that is unlawful or wrongful. No one deserves abuse, period. Abuse can be emotional, physical, or sexual.
She'll be 18 soon, Until then, keep her away from your other kids as best you can. Narcissists destroy people. Here is what you don't do with a narcissist. J.A.D.E. Do not Justify - Argue - Explain - or Defend yourself or your actions.
My mother was a grandiose and vulnerable narcissist and the my father keep himself busy doing volunteer work during his retirement. She was brutal to him and to my sister and me while growing up. When she'd get drunk her behavior got worse. Eventually she got kicked out of her bridge club for her antics.
She told horrible lies about my sister, my father and me. People who didn't know us well believed her but a lot of her friends didn't.
There are some wonderful video on youtube about narcissists, sociopaths and borderlines. Google Cluster-B personality disorders and you'll see what I'm getting at.
I don't think there's a cure for these people. That's the general consensus of the mental health profession,
Because she's you flesh and blood it will be tough for you to cut her loose but there probably isn't any other way. It's debatable as to whether these people are mentally ill. I think they are just bad people.
You may want to provoke her into hitting you and have her arrested. Jail won't cure her but arrests and convictions will give you some leverage until you can legally kick her to the curb.
Again, narcissists, borderlines and sociopaths generally don't respond to therapy.