Hello Corvidae, and congratulations on those results! I do not have access to the GAI tables (although I have searched for them as well!), but here's what I know. You add vocab+similarities+matrix reasoning+figure weights+block design to get the GAI sum of scaled scores. Then you take that sum and enter it into Pearson's table to find the GAI.
I believe that on the WISC V, a sum of 84=GAI 144 and a sum of 87=GAI 148, so your child's sum of 90 would put her GAI very near, if not equal to, her FSIQ.
As for extended norms, there are folks here that know plenty more than I do about this, but it appears that they might be applicable in some sections.
