Hi Ambitious202
Having a parent with BPD can be quite difficult. I am glad you had the support of a therapist to help you with this. Having a solid support network can be invaluable, that's why I'm also glad to see you reaching out for support here Are you currently perhaps still seeing a therapist to help you process all of this?
Congrats on your upcoming baby niece

Sorry though that your mom is dealing with it in such an unpleasant way. You mention the silent treatment, has this been going on since your mother received the invite to the baby shower or already before that?
Is giving the silent treatment something your mother does often?
It can indeed be difficult to understand why people with BPD behave the way they do. At the heart of many of their issues often lie distorted thinking and perception, an unstable sense of self and an intense fear of abandonment. If your mother indeed has BPD, her behavior likely stems from her distorted thinking.
Take care and welcome to bpdfamily
The Board Parrot