Hello, BlueSky. Welcome!
After going over them with the psychologist I realized that she scored 100% on four sections
I'm sure aeh will chime in here, but I don't think a 19 is "100%." I believe that is a percentile rank , which again, isn't "100%" but is more likely > 99.9 percentile (meaning, greater than 99.9% of the people who took the test at her age scored lower than her).
Even if extended norms should have been used, from my understanding right now it could not raise her score because they stopped testing once she scored 19 points and did not go farther. Am I correct?
I don't believe this is correct. "19" is not the number of answers she got correct; it is a reflection of the percentile rank. There is very strict discontinuation criteria that has to be met before the psychologist stops administering the test. She may have hit the ceiling, but she may not have.
In your case, she has 3 19s. You should definitely ask for extended norms. That will scale her percentile rank on subtest scores up to a possible 28 (though each subtest has a different scale) and could very well take her FSIQ higher.
I'd also look into General Ability Index (though I'm not sure if you can actually calculate a GAI on extended norms).
More info here:
http://images.pearsonclinical.com/images/assets/WISC-IV/WISCIV_TechReport_7.pdf
