1) Confront the BPD daughter directly
2) Do nothing and let her have the win
Another option- make the day special no matter who comes to dinner. I am glad you have a party planned later. Still have the dinner with your D and she can be your focus.
I recall a college graduation where my parents started arguing during a graduation lunch. He and BPD mother returned to their hotel together, presumably to continue their discussion? I spent the rest of the day on my own.
By getting into an argument, the focus was on that, and BPD mother, not on me, the graduate. I don't recall every argument they had, and don't expect to have been the center of attention all the time, but I recall this day because, it was my graduation.
My guess is that your BPD daughter takes a lot of focus for you and the family with her drama. If it were me, what I'd say is that- your child wants your attention, and your time and your focus on this day. That's probably the main thing for her.


