I cut my sister off to protect my child

My sister has BPD and it makes having a relationship with her incredibly difficult. she has always been my bestfriend. My husband is white and I am black and that’s always bothered her. When I first met him she hated him. The one thing she told me not to have kids with him. She doesn’t understand being with someone for anything other than financial gain. Her ex always spoke so poorly of my husband simply because of the color of his skin and it caused a huge riff in my relationship with him and her. Last week we had a falling out where she randomly started attacking me. The argument started with her telling me that I needed an escape plan to leave my husband. I needed to remove him from my child’s birth certificate and put him on child support because she didn’t want me to be with him. when I didn’t agree with her she lost it. I had a high risk pregnancy and my daughter was at risk of being born three months prematurely. I was placed on bed rest with multiple appointments each week it was the hardest thing I’ve ever had to go through. Constantly in and out of the hospital followed by an incredibly traumatic birth. The day we had a falling out she said to me that I deserved everything that happened to me during pregnancy because she told me not to have a baby and especially with him. It shattered my heart. How could you say that about your niece and how could you say that to me. She spoke on my in laws and equated them to slave owners claiming they saw me as less than. It was all so disgusting. My in laws took her in for Christmas when she had nowhere to go despite not knowing her. They bought her Christmas gifts and made her feel nothing but welcome. I had PPA and an irrational fear that someone was going to take my child and she fed it daily by telling me his family was better off than me and my husband and they were planning to take my child from me. I thought about my child’s future and being around someone who spreads such nonsense and vicious lies about her family and it made me question if she would spew this bs to my child as she got older. I ultimately made the decision to block her. She my only family and I’m distraught but I really do feel I made the right decision for my family sake. My husband and his family keep asking if I’m going to unblock her and work things out because of her BPD I know she’s not stable but what would you do.