kcab is right on the nose - humility has to be based on something, and it doesn't sound like your daughter is getting any useful input in that department. If she's constantly working with people who aren't her intellectual peers, what can she possibly take from that besides frustration and a sense of superiority? She needs to learn to respect others, yes, and to be kind when their abilities don't match hers. But as for humility, for gifted kids, an accurate self-image can often look like an inflated one. As I've said to a couple of my friends in the past, it's only a superiority complex if you're not ACTUALLY superior.
This is so true and one of the main reasons that my DD won't continue in public school. She is getting this mentality.
