Kids don't turn into grownups overnight (thank goodness) and so dating is a relative term. It's understandable to have a crush when you're 12, but I don't think kids should be dating (one on one) until they are at least 16. At this age, I think it's great if kids can hang out in a supervised group. Maybe have her crush over for homework, watch a movie, or stay for dinner. That's great that you have a good relationship and now is the time to talk about all the serious stuff as she is more apt to listen and trust you now (soon enough she'll be depending on her friends for information). Remember all the things you wish someone had told you at this age (crushes, hurt feelings, learning who you can trust, etc)