Thanks all. Lots to look into!
I, too, would recommend the American Girl books and that other one mentioned about girls and puberty. Both my girls have known about puberty and the reproduction since they were little (who knew little kids could have such questions!!!), but experiencing it in real life is different!

Sorry to harp on DD's size. She gets tired of having 2 and 3rd graders lord over her (they think she's younger). Although she told me that she's getting really good at giving them a cool look and stating calmly, "I am a 5th grader." and setting them straight. A fellow 5th grader told DD, "Go away little girl" the other day. DD fumed all the way home. And then our pediatrician, upon hearing that DD was moving to 6th grade this Fall was horrified - "She will be the smallest one there!!" Sigh. This grade skip has gone so well (getting 4s which are like A's), but just some blips every now and then.

I really need to think about the best friend issue. I will definitely talk it over with the SW and AG teacher. Clubs - yes definitely. She will be in band, too. That saved me in middle school way back when!!