I recently made my hand black and blue from punching the ceiling of my car so I didn't hurt my husband. Ya, I would say it can be a part of a BPD diagnosis.

Take this for whatever its worth, no one will probably like it, but its the God's honest truth:
Pot is wonderful for my symptoms. When I used to smoke, I felt like I could be myself. My emotions were leveled out instead of being at the the opposite ends of the spectrum every 5 minutes, I could control my anger MUCH MUCH better. It even helped me focus better on my schoolwork. It was a miracle for me, and one of the reasons why I believe in medical marijuana, and not only for pain management. The only negative side effect I had was weight gain.

The pot could definitely be her self medicating for her disorder.

Also, people with BPD can be "master manipulators" as its called sometimes. Yet, we can't use it as an excuse to do what we want and treat people like trash. You're daughter needs help. She also needs support: You need to be there for her, but without making her feel rejected and unwanted. There are a lot of online resources for family members of people with BPD.