You probably can find someone giving it, especially a private evaluator (less likely to have the budget to buy a new test), but remember that this last child will not really be compared to the same standard as the other children, as the WISC-IV normative standard is 13 years old; they are being compared to children who were born 13 years before they were, not to their actual age-peers, which kind of defeats the purpose of age-normed deviation IQs. The older siblings were closer to the date of the -IV norms.
