Hi Pico96, welcome

Hi. This is my first post and I need knowledge and support in dealing with my adult daughter. She has narcissistic borderline personality disorder but is in denial.
You are most definitely in the right place for knowledge and support, lots of parents here will understand what you are going through. As to the knowledge, there are lots of articles here to help you with that as well as tools to teach you new communication skills, these can be found to the right

I suspect that my son has BPD traits, he is undiagnosed and in denial that there is anything wrong with him, preferring to believe that it is me, my husband and one of his sisters who are the problem, so I do understand what it is like when they are in denial, like your daughter.
It must be really frustrating for you to have her allow her “deadbeat dad” back into her life again while she has pushed away all the loving people who have cared for her since birth.
I am sorry to hear that in the past 2 weeks she has both snubbed her 84 year old grandmother and for no reason has stopped you seeing your two grandsons, it must be really difficult for you to deal with. Is she still maintaining contact with you? x