this is a really late reply. SORRY !
what is your daughter good at ? what does she excell ? her hobbies ? i'd suggest to really dig into what she likes to help boast her confidence.
Also, its good to have a favorite place to be, even if its in her head. if that makes any sense. a place she can go to and just be her, chill out and gather herself. Once she understands she can't stay in that place
i wanna say it gets better but it doesn't. consuling sounds like a great idea also.