We have seen our daughter's heart get broken over the last few years, before we knew that she was gifted and we didn't understand what was going on. In K and 1st she chose one child to befriend and then was devastated when they told her that they didn't like her anymore. She even went to them later and asked what was happening, and the little girls could not answer besides "I don't want to be with you." The teachers told us that she would often play by herself on the playground. It was so painful to see our little one so hurt. She made the decision then (she told me this) that it was easier to be by herself.
We have done social skills groups, and she is currently in Girl Scouts, chess, and Sat. culture class and dance. She seems to have better conversations with older girls, but will actively play with girls her own age.
I am hoping that since she is crazy for photography and film editing that she will find kindred spirits in a summer photo camp.
So, no big ideas - still waiting here for "good" friends by finding the right fit in a common interest group.