Running on zero sleep here so forgive my post (DD has been throwing up all night). I can't help but link some of what you describe to what I have seen with my daughter at an early age but it was with family member's praise since she was shy in public and didn't really 'perform' was just tight lipped. It was when we witnessed her doing some of her amazing things that we got excited and voiced that excitement and DD would clam up. Did you have this type of experience with her in her early years? We think it has to do with her perfectionism. So we (the family) learned early on not to make a big deal out of her achievements but this doesn't mean the general public would understand that. I'm just pondering if this is part of perfectionism at a later age?
