Once you determine how her behavior affects you, and specifically what behavior causes this, YOU WIN. You will never have to own her behavior again, and can allow her into your life, on your own terms within your own boundaries.... and don't own her stuff.... kindly ask her to stop, or leave or whatever when it begins, or just point out that you won't allow that behavior in your life anymore and why.... sometimes it's good to have a meeting just to talk about this, and establish ground rules, based on your experiences and your boundaries... so that you can move forward and she knows exactly where she stands and why.... then if she messes up, she did so aware of it, and it was a choice... and you can then make your own informed choice without feeling guilty..... it works. honest. and not just with parents, but especially with any family member that you care enough about to continue a relationship but with rules....