I think Mia is 100% right: observe. That is the best thing. And then take your child in and see how she does in that environment. Seeing DS actually in Stepford World made it very clear that it was not a good fit...
Also, talk to parents, especially to those with HG+ kids. Ask lots of questions of the teachers about how they handle difference of all sorts, not just GTness. (After all, how they handle religious difference or kids who are slower learners than average might tell you quite a lot about their philosophy regarding individuality and learning.) Ask about the fastest learner they had and how they handled it. Ask what they would do if a child spent all her time in one area or on one activity. Ask every question you can think of!
But the moral of the story is that until you go see in person and talk to everyone you can find about how this particular school is, you *are* back at square one!
One thought: if you put her in and it doesn't go well, can you pull her out without losing your shirt? If so, it seems to me that since you're considering keeping her home anyway, there's no big loss if it doesn't work out, right?
Also, what are your other options? Is this the only school you're considering? Does she have to go this year, or could you send her next year?
I'm just thinking here...
