Here's one idea -
Let your DD run ahead as fast as she wants to go at home, with sports or arts in the afternoon with agemates, and then when she hits 'Middle School' level work, apply to
http://www.davidsonacademy.unr.edu/They are a Middle School and High School, free to Nevada residents, and quite used to young children being able to do Middle School Level work.
Maybe a year or two from now. That way she will be with kids who are 'really' on her level, AND be learnig. If I could uproot the family, that's where I'd be in a heartbeat.
My hunch is that they wouldn't push her to graduate until she was really ready.
Smiles,
Grinity
