The confidence interval for a FSIQ is going to cross over the 130 mark so that your child's true score is likely to fall within a range of scores around the 129 score. WPPSI-III norms, for example (that's all I have to refer to) set the 95% CI at 122-133 around a score of 129. So I'm saying the reported score is not really your child's true score necessarily, the error variance within the test means that FSIQ can only ever be an estimate.