ETA: I hadn't thought about privately testing with the cogat. Not a bad idea.
I may be wrong, but I don't think that you can do this. The only two places that I know that distribute the CogAT to testers outside of the school system, Triangle Educational Assessments and Bob Jones, both have agreements with the publishers that they will only allow homeschoolers to use them. They require the person administering the test to sign a statement that the child is not enrolled in public school and is registered as a homeschooler. I believe this is in an effort to avoid having parents cheat by testing their kids once before the school testing and coaching the answers so they'll score higher when they take it a second time shortly after at school.
I know that's not what you're trying to do. I just am not sure if you will be able find anyone to give it to her outside of school, though, for these reasons.
