Hi zachariacj,
Welcome and hello

Having a name to describe what it is helps to explain so many confusing and painful behaviors.
Was there a crisis that led to your daughter's diagnosis?
Does she accept the diagnosis? How do BPD traits present in her (there are so many variations).
I remember reading that BPD is like have an emotional third degree burn while on a roller coaster.
Sometimes, the silence is about removing themselves from interpersonal stress (always higher with family members) to regulate emotions. The hard part is that people with BPD have a hard time taking responsibility, there is often so much blame, as well as cognitive distortions of what in reality happened.
I'm glad you found the site, and sorry for the difficulties that bring you here. There are (non-intuitive) skills for us, as loved ones, that have to be learned, and that can prevent things from getting worse, even if they can't cure BPD. We will walk with you on this journey, as you learn about BPD.
Many hugs to you
You are not alone.
LnL