Thanks again for the feedback... Her school really is very supportive (it is an independent charter and they specifically provide individualized educational plans to all of the kids). Working individually brings out differences.
She actually doesn't feel self-confident, though. I think it's perfectionism. She constantly feels other people are better at things than she is. It's sometimes true (e,g., she has a friend who is much better at video games than she is and almost everyone she knows is better at athletics), but it's also that she can't live up to her own standards. She does really work with the other kids on projects and enjoys it; it would be completely true if she emphasized that everyone worked together when kids comment on her group finishing first.
I have a son who is also bright (he is accelerated a grade for part of the day), but who isn't like DD. He has been happy at school from the start and it has just been so much easier than trying to make things work for DD. We had thought he might be 2e and always expected it to be harder with him. Instead, he loves school.
DD's recent report card came back with a comment about how she is a role model for the class. That's very nice, but it's also pressure.