Hi bniwelt,

I'd like to welcome you to bpdfamily. I'll answer with I understand your post, if I have something wrong please feel free to correct me. We don't have to assign a pathology to everything, she has a serious mental illness, the mental illness doesn't define her as a person, BPD is not an adjective.
That being said, we can't read someone else's mind, I don't know how she feels. My guess is that there's tension in the main r/s, think of a pressure cooker she's seeking a seconds r/s to release pressure in the main r/s, think of a release valve. Have you given thought about what if she goes back to the main r/s? What do you then?
Karpman Drama Triangle