Have you observed her in a group of kids? That might give you a better idea of what is going on.

DD is the same age (but grade 3) and hasn't had a hard time making friends, but in second grade in particular there was a lot of drama with the kids (esp. girls). This year she is either in a very nice class, or the kids are all just a bit more mature. She was also on Concerta last year and then Adderall and both of them made her moody as they started to wear off (which seemed to be the middle of the day). Adderall in particular made her kind of a basket case. She does much better with her mood and getting along with people on Daytrana. When she is not medicated at all the other kids tend to irritate her (and/or overstimulate her) a lot which can cause her to lash out. Not great in terms of making/keeping friends although she has always been so social I suspect she would always have friends anyway. If anxiety is combined with ADHD, it could potentially cause a lot more social problems.