I have read that it's typical for gifted kids to have processing speed and working memory scores significantly below their other scores but have never seen any numbers attached to that statement. Can anyone tell me how much is too much? Our psychologist thinks my kid has ADHD and he might but I want to be careful not to read too much into something if it's "normal" gifted kid stuff. His WISC-V scores are...

Similarities 19
Vocabulary 19
Block Design 14
Matrix Reasoning 19
Figure Weights 18
Digit Span 11
Coding 11

GAI 151
FSIQ 141

Our psychologist is in the process of figuring out the new extended norms. She said his Verbal Comprehension Index is actually 168, but I'm not sure how/if his Fluid Reasoning or GAI/FSIQ scores are impacted by the new norms. Even without extended norms he has a fairly large discrepancy going on. Does this necessarily point to ADHD and/or a learning disability or is this typical for kids in this IQ range?

Any insight is appreciated, thank you!

Welcome!

In the special group studies, the mean PSI scores for the gifted on the Wechsler family of tests have historically fallen in the High Average (110s) range. Solidly Average scores such as your DC obtained on the one PSI subtest administered (likewise the one WMI subtest) aren't a red flag in and of themselves, but may have additional clinical meaning in a larger context.

The extended norms very well may affect the GAI and FSIQ, if the VCI rises that much. You still have MR, too, which may be impacted by the ExNorms.

The GAI-CPI (WMI & PSI composite) difference is substantial enough that NAGC is recommending that a much broader range of Indices other than FSIQ be used, especially for 2e students.
https://www.nagc.org/sites/default/files/Misc_PDFs/WISC-V%20Position%20Statement%20Aug2018.pdf