This community has been so helpful in supporting me, and I know that I have a tendency to only post when things are at their worst. I suspect that's when most of us find this place. But I thought I should weigh in on what it looks like when things are quiet. I know I've found it comforting to read here when others have been in that place.
I hadn't talked to my uBPD mom since Easter of 2018. Trying to make sense of things in the immediate aftermath of that particular rage incident brought me here (and into therapy), where BPD and covert NPD traits described so much. I have been NC with my mom (aside from greeting cards on holidays), and LC with my dad. They are married, and I gather that he isn't really allowed to talk to me unless she is in the room with him.
Between my father receiving a cancer diagnosis earlier this year and COVID-19, I've spoken to my mother a couple times on the phone. I keep focused on facts, emphasizing that I love them and am concerned for their health, and get off the phone promptly when she starts veering into

territory, e.g. she wants to catastrophize or vent about my father's choice of treatment. (FWIW, his cancer was found very early, and is very treatable.)
Two years ago, I thought about reaching out to an older cousin, but had a lot of reasons not to: What was I seeking, after all? Was I just trying to triangulate in the same way my mom does? Could I trust her, or anyone in my family? Would she be offended about what I was insinuating out my mom, and hers? So I waited until very recently, when I knew I wouldn't be going into that conversation in a very fragile state.
Oh my goodness. I think she had been waiting for that call for years. Her mother and mine are sisters, and share a lot of similar traits. Her mother was diagnosed with BPD many years ago, and has been quite abusive to my cousin who, thankfully, was willing to talk openly about this. I learned about how our grandmother also had a lot of these same emotionally abusive traits, but it dissipated with age and with the death of her abusive, alcoholic husband.
I don't know about you, but I waver back and forth between calling the emotional abuse what it is and gaslighting myself. It was so powerful for someone who knows me, and has seen me interacting with my mother, repeat back to me the things that, deep down, I know to be true. Things like,
"You don't need to apologize for staying away [from extended family]. I assumed, I think we all assumed, you were doing what you needed to do to be safe from your mom."
"I could always sense a tension, just a basic personality conflict, when the two of you are together. You are very rational and logical. Your mom, well, we have all observed or experienced her being extremely emotional and controlling."
"It isn't anything new. Even when you were very small, I watched your mother be extremely controlling of you. Even before you knew it was abusive, she was being abusive."
It was abuse. I'm healing. And it feels good to know that I'm not alone in that process.