Thanks for the replies. I'll have to look into the legal issues--I was really hoping that someone would know definitively if they were required.
My issue with the testing is more an overall issue with our school--DD is already in the gifted program, but I suspect they are deliberately holding her back so that she can boost their scores. The principal has said several things that make me believe this. I don't like to see my kid treated that way, but I'd like to get their attention. They'll acknowledge that she's bored, but God forbid that they challenge her. It's just really stupid. The principal even told me the kids would be better off in a more challenging private school (but, of course, he wouldn't be shelling out the $12k per child per year, so, easy for him to say!) Like I said, I'm not one to make a fuss, but I'm beginning to think that I must, for the sake of my children, and this seemed to be a way to get the school's attention by potentially affecting their outcome (yes, she's really good enough that she will do that!).
As I type this, it sounds kind of petty. But this kid has been begging for harder stuff since K, and gets really dumb excuses form the school as to why she can't have harder work (like, for example, she reads 4+ grades above her grade--but is stuck in the highest level reading group, which is still 3 years behind her ability. They refuse to do more. Her brother is 7 and even worse--reading at a high school level!). But the school's attitude seems to be that, since they're not failing, they must be okay. But they're not--they're dying inside, and the school doesn't care.
P.S. Don't even suggest I transfer them--the pricey private school is a long drive each way, I would have to drive them, and we'd have to kiss our other activities goodbye. Sorry for the long post!