Cricket, My dd also is an "out-of-the box" thinker and has struggled with standardized tests. In every case when I have had the opportunity to see the question and ask her why she answered the way that she did, her response is a legitimate interpretation just not the standard one. I've read that this is not uncommon with gifted kids. I don't have any words of wisdom but know that your dd is not alone.
Dd is definitely out of the box. This was drilled home to me when she came home with a math exercise in 3rd grade that said something like, "how many rectangles in the figure at the right." On the right side of the page there was a figure that showed a rectangle cut into fourths with a cross drawn down the center. Dd answered "three." I was at a loss as to how she'd come up with that in that there were a minimum of four rectangles if you only caught the four quadrants. She was looking at the right side of the figure (i.e. - the figure at the right) rather than the entire figure and counting the two quadrant rectangles as well as the one bigger rectangle that enclosed both of those quadrants.
