Since this popped up and I have an answer, here's our experience... DD took the WPPSI shortly after 4.5 and her FSIQ score was 137. There was a lot of variation in a few of the subtests, which the tester couldn't explain; in hind sight, perhaps related to her ADHD or vision issues which were not well treated at the time. At the time the tester stated in the report that DD would likely test higher in the future.
She took the WISC-IV recently at 8. Her subtest scores were fairly even across the board and her FSIQ went up nearly 20 points. She's also taken the CogAT and WIAT-III within the same month, and the school psych gave her the RIAS last fall, and the results all suggest that her recent WISC scores are fair measures. Since the original test, she's also gotten medication and therapy for ADHD.
Oh, and FWIW, suffering through nearly 3 years of public school has not evened her achievement levels out with the rest of the class. Though I can see how this situation could, with a child with a different personality or more non-academic interests or better social awareness than DD.
