Hello
wolfman I am so sorry you've had to find us but I'm glad you did, that you have some insight to what may be going on with your daughter. I'm sorry to hear you've been struggling for so long with her behavior. You must be exhausted.
I want you to know there is hope and you've come to the right place to learn tools and gain knowledge about BPD. A good place to begin is the thread pinned to the top of this board,
HOW TO GET THE MOST OUT OF THIS SITE. It's got many of our best articles with links to more - I'm sure you'll find something there you can relate to, you are not alone.
What are the behaviors that led you to suspect BPD? Do you agree with your sister that your daughter is a bully to you?
I look forward to getting to know you and how we can best advise you.
~ OH