Originally Posted by concernedmom2019
the gifted program... little differentiation or support in the regular classroom and nothing much happened in the gifted time 2-3 hours per week.
Unfortunately, this is common in US public schools since the introduction of Common Core and the change to rating/ranking teachers and schools based on reporting equal outcomes for all students; this often involves capping the growth of students at the top.

Originally Posted by concernedmom2019
WISC-V FSIQ 129, GAI 134...Stanford-Binet FSIQ 109... I cannot see how the two test scores can be equivalent. Can anyone advise about this?
Measuring IQ is not an exact science like measuring physical elements such as height and weight. Although the scores of various test instruments differ (as summarized on this Hoagies page), each test would indicate the percentile (percent of the population above which the test taker scored).

I'm linking to a recent thread, The story of an unidentified GT child, which I found inspirational and thought you might, too: opportunities can be found to challenge one's self, outside of a gifted program in school.