When we spoke yesterday the director said that she was too young for the IAS. They do have the IAS, but use it to evaluate kids for gifted not grade acceleration.
That makes absolutely no sense at all. The IAS is a scale that is filled out specifically to evaluate a child for grade acceleration. It isn't a test and is not supposed to be used to determine if a child is gifted. Having been through an IAS process with one child when she skipped 5th, I can tell you basically what it looks like.
First, it asks about the child's willingness to skip a grade and a few other critical pieces such as whether a sibling would be in the receiving grade, etc. It has a section for test scores: achievement scores from grade level tests, IQ (although I understand that group ability tests can now be used), and above level achievement if you have them. Then there's a piece on factors like the child's age in relation to grade peers, size in relation to grade peers, etc. The rest of it is somewhat subjective and filled out by the teacher indicating how motivated the child is, how he gets along with younger kids, older kids, age mates, teachers, how well he completes classwork, etc. Finally there's a section on support from the school and family for a grade skip.
I don't even see how they could be using something like that for a GT determination!

It makes one's head spin!
I guess in your situation, I'd do some real introspection as to whether you think a grade skip is the best route for your dd. If you come to the conclusion that it is, I'd go in with A Nation Deceived's executive summary, the support from the principal, her MAPS scores and a letter stating that you take full responsibility for the outcome of the skip and then push for it.
If you're not sure on the skip, think about what else would really work for her. If they are ruling out subject acceleration and GT pull-outs, what else can they do for her? I've never been highly impressed with the in class enrichment approach when it was used with my girls.