If she's saying she wants you to go hard on her because she feels genuinely guilty and she thinks she deserves it... Kinda sounds an awful lot like it's less of a kink thing and more of a "self harm via you" thing. You had her consent (sort of--no safe words is a bad plan always and inherently blurs the line between consent and no consent when things get intense), but even having consent doesn't mean that it can't still be harmful. Lots of people with trauma reenact it in ways like this, and while it can be fun and even healing if it's done properly, it can also 100% be very damaging and retraumatizing if it's not. Not saying that's her situation, but I wouldn't rule it out. Y'all really need to talk about this stuff.