Rape and Rough Sex Issues

So basically, my SO was raped a while back before we started talking. When we got together, it was something I helped her get through and now we have been together for a little over a year. I am her first real boyfriend and the only person she has given herself to/had sex with, willingly of course. So my issue is, because of what happened to her, I feel as though I cannot indulge in my sex life. I like passionate sex and rough sex and everything in between. But sometimes, she'll text me naughty things telling me she wants rough sex. And it is iffy for me because I have this crazy idea that it is derived from what happened to her. And she might want that again, or she only says those things because of what happened to her. So I've never been able to go full out sexually because I don't want to trigger the wrong thoughts or emotions in her. It just feels plain weird to me. Because normally I'd love to have rough sex and stuff. But I can't bring myself to do it with her because of what happened. So am I just overthinking it? Should I just do it anyway? Should I tell her about how I feel? Am I wrong?

tl;dr- girlfriend sexually assaulted a while back before we started dating. I like rough sex, she shows signs that she does too. But I can't bring myself to have it with her because of what happened to her. What do? Thank you!