Aww poor thing, but aslong as she seems ok.
Tinks your children are wonderful, they have a great mother and they really seem to have their heads screwed on correctly.
All i can suggest is to be honest with her, let her know your there but that she needs to make her own choices (and inevitably mistakes) and just make sure your there to pick up the pieces... i doubt she'll do anything foolish.
^^yeahthat

It's got me thinking though, that it's probably important at that age to learn how to interact with boys as more than friends. I sometimes wonder if forbidding boyfriends until 15 or 16, when sex is more likely to be an issue, makes it more difficult to navigate a (possible) physical relationship. Does that make sense? Not that I'm saying they start getting physical at 12. But its important they have some emotional and social experience before they get to that point.

Talking in general here, not in your DD's particular case Tinks.

ETA - Be interesting to see what I think in 12 years time