It's quite possible this psych hasn't ever seen IQ scores that high - although we've never had a comment exactly like that, we've almost always had initial comments from evaluators that our EG ds has seen that made it obvious that the professionals were not used to seeing high IQ scores among the kids they work with. But that was all that it really mattered - once we were past that first look of surprise, we never had issues with getting what we needed from evals or remediation/etc for ds' disability. (I'm referring to private evals/therapies here... there was a huge wall to climb over to get any help from school).
I want help addressing the dyslexia and adhd so this kid can function in society. She says they are intertwined and it is important to know exactly. So if the IQ is X vs. Z, why should I care.
I don't think that it's the X vs Z (total #) that matters - it's the differences in subtest scores on IQ tests that can give insight into potential LDs. I'm not sure how old your dd's first set of testing was, but when our ds has had updated evals they have included updated IQ tests, as well as updated achievement tests, as well as additional testing to get to the root of what was causing discrepancies in the IQ and achievement testing as well as challenges with academics etc.
Does it really make a difference or are we getting asked to do more testing that we really don't need? Why is this so hard???
No question about it, this is *hard*. But a huge part of what will help is having as clear of an understanding as possible of your dd's challenges, and also having a good road map to follow forward to accommodate and remediate as appropriate. This may sound contradictory to everything you'd expect to hear from a parent on this forum, but I do believe that it was a *good* thing that when our ds first started obviously struggling we saw a neuropsych who sees children who are struggling with LDs... I think that made more of a positive difference for us than trying to see a psych who specialized in gifted children.
I'm curious - how old is your dd's IQ testing? Is it less than 2 years old? Do you have the subtest/etc scores?
I mentioned above that our ds had IQ/achievement tests repeated each time he had another eval (he had an initial eval, a few years later he had an eval as part of the IEP eligibility process, a bit later he had a private eval to prepare for middle school. He also had a very early round of IQ testing for entry into a gifted program going into elementary school. Out of all that testing, his GAI/FSIQ/etc never varied much at all. So... I suspect your dd will still have a high IQ score

Last thing I'll add - I've mentioned my ds as an example. I have two 2e kids. My younger dd is dyslexic... sorta. Not traditionally dyslexic but has a very definite LD that impacted her ability to learn to read and still, in middle school, after years of tutoring, impacts her ability to comprehend fully what she is reading - at a level that matches her intellect. The reason I didn't mention her as an example - her challenge is *really* complex. She's been through several types of evals - one extremely thorough by a reading specialist, and I still am not sure I understand what is really going on and how it impacts her. Yet even though I don't thoroughly understand what's up, I don't regret all the evaluation and testing. Each test and each piece of input from professional evaluators has provided more data that has been important to helping us help dd.
Best wishes,
polarbear
eta - I'm not sure what the context was in which the psych was referring to the WJ-III Achievement tests as "not being adequate", but it's been true for both of my 2e kids, and my dyslexic dd in particular, that the WJ-III Achievement tests were just confusing due to impacts of their 2nd e, rather than illuminating in any particular way. DS' tests reflected a meaningful pattern due to his handwriting challenges - but also were skewed in terms of not reflecting his true achievement due to his handwriting challenges. DD's WJ-III tests were actually higher scores in some instances than her ability testing, and don't reflect the impact of her reading challenges. If the psych was referring to the WJ-III tests as being "not adequate" for diagnosing and understanding learning disabilities or other types of 2e challenges, I'd agree with the psych.