Our school uses Dibels as a grade level test to look for deficits. If the goal is 10 - they don't care whether you get an 11 or a 20 as long as you are not below the goal. Even my gifted dyslexic reached the goal on Dibels.

On the other hand, MAP is a "smart test" that does not ceiling at grade level. It keeps getting more difficult until the kid meets the discontinue criteria. If your kid is in the 99th percentile for grade, I think that you have a good argument for more difficult text.

With some of the lower level non-fiction texts, we've seen interest level affect performance. If my kids weren't interested, their performance suffered. Maybe you could ask the teacher to let her try the "V" level work? Does he/she seem open to discussion?