tortuga, I agree with many of the PP. I would suspect that in your DD's case, the WISC FSIQ alone is not a great indicator of her potential or abilities. I do not have time to look up the sources at the moment, but I've recently read cautions about simply utilizing an FSIQ to understand a child's abilities. The GAI would probably be a better measure to understand her. Also, your DD may be an one of those children who simply performs better on a SB, or other type of test.
If someone doesn't beat me to it, I can try to post sources later.
