I'm not going to even try to debate whether or not you can improve IQ scores by prepping for the test, but since I was the poster who mentioned having a dd who tested gifted at 5 and since then has tested twice at a lower IQ, I wanted to add that in her case, there was no test prep - in fact, we weren't even taking her in for IQ testing, she had an unexpected IQ test as part of a psych work-up for anxiety.
rhondau, do you have the subtest scores from your dd's IQ test? If you do, are they all consistent across the board or are there any scattered highs and lows? Although it's not likely, your dd's experience mirrors my 2e ds' quite a bit - gifted traits at a young age, gifted IQ score at a young age, school performance doesn't match expectations based on ability, high anxiety experienced in early years of school. My ds was also in counseling for anxiety when he was in first grade. It took until the end of 2nd grade when what seemed like average performance in school slid into below level performance and his anxiety really *really* ramped up for us to take him to a neuropsych, and that's when we discovered he had a disability that was severely impacting his ability to function at school, and that was the source of his anxiety.
polarbear