[m22] getting closer to relationship with [f21] - she likes me but still seems to be healing from past relationship, how to approach this?

Been dating for 2-3 months, no sex because she likes to take things slow physically, we see each other a few times a week because we have busy schedules so it doesn't really feel like things have developed too far. We both clearly like each other. Definitely some deeper discussions about ourselves, etc.

So two weeks ago in the middle of a deeper conversation I brought up (fairly naturally based on the topic) that I wasn't interested in seeing anyone else and would be fine being boyfriend/girlfriend if she'd like. She said she just got out of a really bad relationship and isn't ready for that label. I initially met her in September and we made out/went home together that night, and the fact that she lives out of town (we go to college together) means that the relationship likely ended last semester, or sometime earlier this year. She's mentioned in passing that she's had a rough year, kind of joking about it but hinting that there are some scars (both relationship-wise and other life stuff).

The thing is, she's a little stand-offish. Initially my friends didn't like that I was drawn to her because of this seeming character flaw on her part, but now it just makes so much more sense. I feel as if she knows she likes me, but subconsciously won't allow herself to really fall for me yet. She seems to assert her independence in subtle ways, to avoid risking being hurt again. I can sympathize for this: she doesn't want to risk letting go of something that could be good, but she might not be ready in some ways. On the other hand, I think I'm entitled at a minimum to not be "led on", which is feeling slightly like what's happening.

Initially I thought she just wasn't into me much, but now this alternate perspective appears to be what's really going on. Her roommates, who I'm friends with, tell me things half-jokingly like "if you break her heart, I'll cut off your fingers"/etc. I think they think I'm not as into her as I am, which I suppose I do a good job of hiding, probably in waiting for her to be more forward in general.

So my question is how to bring this up? I'm sort of new to approaching touchy subjects, and while we've gotten into our own lives and perspectives on things, it seems like past relationships are taboo. I want to be there for her and support whatever she's still going through, if she needs me to be - or is this something she needs to get through on her own?

I'm thinking about just letting her know that I like her enough to give her a little time to continue healing, but I don't want it to sound like it's something I'm waiting on the sidelines for if she needs to lean on me. On the other hand I don't want to stress her out by micromanaging a very personal thing in her life.

tl;dr - should I [M22] help [F21] heal from past relationship or let her take the time to do so herself?