That kind of discrepancy is probably pretty common even in HG children, and in PG ones, it's a rare individual that doesn't have an asynchronous area of (relative) weakness.
It's not that they are not going to eventually have a high level of performance/mastery-- just that at the moment, that particular domain is in the shade of the other areas of strength.
I'd actually go so far as to say that this is THE biggest problem that I face as a parent; how to manage that asynchrony so that DD doesn't internalize it as "I'm not good at," when that is the only really logical thing, at least in context.
She's a VERY good writer. She's a VERY good mathematician. Just not PG in those two domains, which have (functionally) limited her academic acceleration, though not as much as her underlying maturity and EF have.
It's a serious problem not just for psychologists, but also for anyone that has to live with this kind of asynchrony.
