When I see posts on this topic, I try to give a perspective from the daughter's point of view and also from the experience of raising teens myself.
I was not my BPD mother's "favorite child" so I can't say she was particularly good to me as a child, but my teen years were more difficult. It's been written that parents with PD's see their children as extensions of themselves, but for a child, a primary developmental task is to establish their own autonomy, which is in conflict with that perspective. Younger children tend to me more easily controlled.
For a teen, becoming their own individual is a main aspect of their development, but teens don't have full maturity. They have their own hormonal, physical, and emotional changes. While truly bad behavior is never acceptable, a parent needs to be able to differentiate between teen age moodiness and that. What is missing in this combination of teen age girl and BPD mother is that, the mother herself doesn't have emotional regulation skills either. In other words, even normal and generally well behaved teens can feel aggravating to parents at times but the parent needs to be the adult in the room.
One of the odd experiences for me as a teen was that in some ways, I had "outgrown" my BPD mother in maturity- and yet, I wasn't mature yet. My BPD mother still had authority over me as a parent but also behaved in ways I would not be allowed to do. She would either be overly authoritarian and controlling with me- or look to me as an emotional caretaker.
It's possible that your D is reacting to her mother in an age appropriate way but her mother isn't responding to this in the way a stable adult would. This also doesn't mean your D can act out in unacceptable ways but you need to be able to discern what requires discipline and what does not, because, if her mother is irked with her, it may or may not be your D's fault.
The one best intervention for me at the time was time away from her. My parents didn't divorce but if they did, I'd have wanted to live with my father. This may not be the case with your D if she has a better relationship with her mother than I did, but her spending time with you will give her some respite from the dynamics with her mother and a chance to interact with you as the more emotionally stable parent. In other ways, I could spend time with relatives, summer camps, after school activities. College for me was a way to start my own independence. If your D has academic or trade skills interests, that can be a path to encourage (not too much pressure).


