Hello ArkGal
Welcome...

...glad that you found us.
I am so sorry you are having to live through this with your daughter. It is good to read that she is currently under the care of a psychiatrist. Have you, as her parents, ever had the opportunity to get counselling for yourselves to work on ways to better deal with her behaviours? Does her psychiatrist include you in any way as he treats her?
You write that she mentioned to you that she is wondering if she has BPD. Did she give any indication what brought her to thinking of that as being her problem?
For sure there won't be any immediate answers for all to be turned around but this can be a starting point for you. As you participate in/on this forum, also work your way through the website...read/learn and work on applying some of the strategies. I so hope you are able to get some feed back from her psychiatrist.
Huat