Unfortunately, I don't think you have much of a choice if your child is smarter than others. As you have said, tutors are expensive. The regular school system is cheap because they are standardized, and everyone is treated the same. If they can cater to each student individually, then they would be expensive as well. The next best thing is to have your child skip grades. That might be good for her studies, but not for her childhood.
This topic also reminded me of my elementary school system. They had a honors section, where the smartest students in the grade are placed. They learn more advanced topics, and are usually together with other smart pupils. There is usually healthy competition between them, and they push each other to be better. It was later abolished, because of discrimination on students [there was also a last section, where students who are lagging go].
From a curriculum standpoint yes, but not from an attention view. Teachers spend most of their time with the trouble students.
I don't think I would want this for her. I would rather her have a steady group of friends her age for now. Plus, she will excel in some areas, but be deficient in others, so if she goes up, she will struggle where she is weaker.
It is funny that being smart is a bad thing. Shouldn't we want the smartest to excel and improve our broken world?