The thing is, if she does have BPD (and I don’t know for sure, but as someone who has BPD and has been in recovery for nearly 10yrs I would say she certainly has many many traits from what I have seen of her) - all the therapy in the world will not help her one bit until SHE is ready to put in the work, reflect on herself and her life and make changes.
She doesn’t seem to be anywhere near that stage yet sadly.
It is one of the tragedies of the disorder - for the individual and the people around them - anybody CAN recover from BPD, but not everybody WILL.
It would have to come from her. She would have to reach a point where she recognises the damage her behaviours (which are simply her way of coping and responding to her triggers and emotions) are doing to herself and those around her. She would need to then be willing to engage in the years of skill learning and mastering it takes to learn and put into practice new ways of regulating and responding to her emotions, learning to recognise her triggers, and understand WHY they are even triggers, learn to separate past events with present day situations and only respond to the present not the past, learn to recognise and challenge negative automatic thoughts, learn to recognise and understand her schemas/filters, and when the might be activated and what effect that may have on her perception of what’s really happening and then challenge that.
Because that’s what it takes to be in recovery from BPD and you have to really really want to do it and you have to keep doing it everyday for the rest of your life.
And I don’t honestly think she’s anywhere near close to even the first stage of that.