I don't remember exact scores, but I do remember my gifted ds12 getting a 18%-ile non-verbal score in 1st grade. I was shocked and baffled. I think it was a lot of exactly what you say - he had trouble processing oral directions and the class was loud. The next year, he easily made it into the gifted program (luckily, everyone was tested in 2nd grade; he had been tested by recommendation in 1st). None of my other kids had that experience with a test that was so off, and he has scored extremely highly on nonverbal ever since. However, he was at the time and still is on an IEP for speech and verbal apraxia/expressive language. He was supposed to be tested separately and when that was done, and he was able to read the directions himself instead of hearing them, it made all the difference.
So, outside testing is definitely an option, but it might not even be needed. For my son, his verbal was very high from the onset, but the nonverbal was stuff he hadn't really seen (the figural and spatial stuff) and I think he just really needed to understand the directions. However, if you think that there is a chance that your daughter has ADHD, I would try to find a good tester who specializes in 2E if you can afford it. My son was receiving services from 18mos on, and I think some of the misperceptions by teachers (he can't speak, so he must be stupid)made for a tough environment. Even though now all his teachers pretty much view him as exceptionally gifted, I find myself still defensive at times, I'm sure as a result of those early years (btw- when I asked why he wasn't tested separately in first grade, their too-quick but honest answer was, "well, we don't normally expect kids needing accommodations to get recommended for gifted testing.").
For us, it honestly did make a difference getting him into the gifted program in 2nd grade (his scores in the fall of 2nd grade were good enough to get him bumped up mid-year). The teachers viewed him differently and then they spoke to him differently, gave him more challenging work, had more patience with his convoluted explanations, etc... I know that this is not how it is SUPPOSED to work. Teachers are supposed to see potential whether or not they're in gifted, and kids can still get enrichment at home, yada yada yada... However, in our case, it actually did make a difference, so if you think that your dd is gifted and would benefit from the GT program, I'd try to get her in, in the next few years if not this year.
Good luck - and don't take those numbers to heart! I spent a week or two wondering if I was crazy, then I just realized that I knew my ds, and every test since then has borne this out.
