I’m going to say NTA, but with a very bit caveat. Even if it gets me downvoted to hell.

Let me clarify - you are 100% entitled to set your boundaries in terms of who you see and spend time with. You suffered an incredible betrayal, and you have every right never to want to see her again. What she did was all kinds of wrong.

That being said, I will never agree with the notion that making non-association with someone else a condition of having a relationship. I was in an abusive situation not that long ago, and when it finally ended, I made it clear to everyone (friends and family) that if they wanted to continue to see or be friends with that person, it was absolutely their prerogative. But I set boundaries for what I was willing to accept. I didn’t want to hear about them or any updates going on in their lives. I didn’t ever want to find myself in the same place as that person. Basically, my boundaries were “You can be friends with this person, but there can be absolutely no crossover, and it’s up to you to make sure there’s no conflict of interest.”