Ignore all the advice you're getting in this thread, OP. Like you said, you already know what to do. You know her better than any of us do, too.
Since we're talking, though, I'll just relay a personal story (i.e. nostalgically rant into the void): one of my exes found a new boyfriend in practically record time after we broke up. That wasn't really the end of us, though. Sometimes you enter into a "the end has no end" situation, wherein managing a state of being over becomes a pure matter of will. Within 3 months, we were hanging out as friends, and it didn't take long from there for her to express doubt and ask me anxiety-inducing questions like "do you want to be with me again?" ("I don't think that would be a good idea" being my hesitant response).
Fast forward a couple years, through a few tear-filled conversations, through me entering into a new relationship and her suddenly asking to see me, etc., etc., and it's obvious that all this time later, there's still a reservoir of romantic feeling.
Sometimes those feelings aren't really translatable to a relationship, though, as you know. By the time I found that new relationship, my strategy toward her had long been "be within reach but don't actively reach out," and we already only talked somewhat rarely. After one last emotional conversation, though, we agreed it would be best if we stopped talking entirely, at least for awhile.
I'm currently in a happy relationship, and so is she. There's no rush to "get over" things, and some amount of confusion is perfectly fine. All you need to do is honestly ask if a relationship with her would really be the best vessel for your happiness and growth. Sounds like you've done that already, and come to a reasonable conclusion.