Going off on family member-justified? Trigger Warning

Amanda💛 • Wife & Mom of 4 ....Trying to figure out the rest!
Okay..so long story short, my mom was raped by her older brother when she was younger(never had any counciling & him no repricutions). She had a falling out with her 2 older sisters about 5 years ago. She asked me to cut them out of my life, I chose to block 1 on social media, but not the other. The one I did doesn't know how to not say/bring past history up, the other basically just posts pictures of her grandkids & was my favorite aunt growing up. I get along well with all their kids. 
So my aunt who I have blocked messages me Saturday asking me to pick up something up of my moms, so I did today. I walked up hugged her, said I loved her, and chit-chatted for a tad. She then asks me why she's blocked, I told her as a sister, I felt like she should of chosen her sister over her brother. That if anyone ever touched my baby sister they'd be dead to me, blood or not. She's like how could you say that about family, I said how could family do that to family. She has kids that I know dang well who have been harmed in her "cult like church", but chose to stay(I was same age as them, during childhood), I threw that in her face, and said she didn't protect her own daughters. She called me a b***h, I said no I'm not I protect my own.  She starting screaming curse words at me, then my shouting them back at her, so she took off bawling. I'm not a confrontational person at ALL, I'm still shaken up.  Am I wrong?