I would add, to ask your DD, if you could learn anything you want, what would you like to learn about? What are you curious about?  (the answers make take a while)  Notice when she does have some answers/questions, does her eyes light up? What does she get really excited about? 
If you do wind up pulling your DD out of school to homeschool, she may need a year to unwind and unlearn the bad habits of hoop-hopping at school. 
 
  Independently test so you can find out as much as you can -- so that you can make better decisions based on better information.  Definitely, it must be a very patient tester who understands gifted *Girls* and the social/emotional needs of gifted girls.
I suppose, just an idea -- don't know if it will work for you, for several weekends in a row, calmly and gently discuss with your DD, let her know you want to hear her and won't judge her for it, but will be accepting of her answers, --- ask her why and what exactly about school she doesn't like?  Let her give you examples. Write them down. Mention these things to your tester later. All specific issues.
Some parents have paid and have brought in the psyc-ed tester as a consultant to help talk to the teachers/administration (because they're the professionals). That is an idea -- depends on if you think that will help the situation at your school. This could be something to think about before the final leaving of the school.
best wishes, good luck, let us know how it is going 

ps. we homeschool