Welcome. It is very worrying and frustrating when our loved ones do risky behavior. Does she live with you ? It is also scary to see substance abuse happening to throw into the mix . Please take a look here. Know you are among those that completely understand and are living a parallel life with you .
Here is a link in the site here about parents which may be a good place for you to start.
https://bpdfamily.com/message_board/index.php?topic=114267.0 Meanwhile, it is important for you to take care of yourself, as you are as important as the BPD child. Some of us( like myself) have our own therapists to come up with coping mechanisms for us. Now it is important to note that us taking care of us doesn't automatically solve the BPD illness of our loved one, but as we become our own friend we can perhaps give the adult child some room for her/ him to figure out that they do need help/ continue on getting help. It is so easy to get lost in their illness and we can't allow that because it does no one any good.
As you are able, please feel free to write in more , like is your daughter in therapy, etc.