They use AR, which is another source of frustration. She has a huge range and always gets books at the minimum sixth grade level because she likes fiction and there is so little at the high school level (by AR standards) in their library that is relaxing reading material. She doesn't like the books intended for older children because they are often about issues that she finds upsetting; they don't have classics that would be more challenging.
I worked as a volunteer in the classroom for several years working with this program. My kid's school stopped using this program above 4/5th grade because at that point the schools switched from 'learning to read' to 'reading to learn'. Plus since our school had many kids who read above grade level the school couldn't find appropriate books at a reading level that were age appropriate and in the lists. (And the school was a K-8) In my opinion this program works best when readers are still in that learn to read phase. To put it in perspective, fiction that average adult reads for 'fun' is only about a 8/9 grade level.
I second the suggestions she uses 'non fiction' books for her AR book. As to the scores, they might not be wanting to tell you because they are relatively meaningless. At this level she might not be improving like someone reading at the lower levels who improve by this measure rapidly. In addition from my memory the higher the level, the longer these tests take. My son more than once just gave up because he got bored of taking the test.
