Awesome! Sounds like the ball is back in your court dude!
Respond to the message but def. wait at least 1 day (remember -- she didn't give you the time of day when you responded too quick but came crawling back when you ignored her). She's trying to make amends and that's probably not easy to do - a bit of a loss of pride on her part; some positive human response on your part would be best (think of all the times you've had to apologize for anything; it would make you feel horrible if you didn't at least get some "it's ok" acknowledgement).
And then, do what feels natural. Hang out with her or stay distant. Whatever your inner-self tells you that you want to do. You're driving through life, and she becomes a temporary passenger in your journey only if you want her to too.
The type of passenger she may be?
Well, that's up to you bro
