Don't know, and honestly, you probably wouldn't want to hear my recent horror story (also have a 13yo DD who similarly found a peer this past summer, but turned out to be-- well, psychopathic is probably the best way of putting it).
I'd caution her about "healthy" relationships, not giving your whole heart too soon-- and boundaries, personally. This is a particularly important talk to have, IMO, because our kids are much more vulnerable to offering themselves heart and soul to anyone that seems actually compatible and seems to return their interest. Trust me, THEY know how thin that selection is for themselves, too, by this age. What they DO NOT seem to know is that there are going to be others. Eventually, I mean.
I understand where you're at, though, and we, too, have wondered what to say to a child who is SOCIALLY so mature, but is also in so many significant ways still very much 13. Do think carefully about what same-age peers are doing/thinking as part and parcel of normal development, here, and bear it in mind. This is very much the age of crushes and shallow attractions-- for MOST kids, that is.
