(Not a teacher, nor a statistician)
As far as I'm aware, percentile rank of 10 (or in the 10th percentile) means that 90% of people were better than the person. If they wanted to say that she was in the upper 10% of the class, it would be "90th percentile".
Perhaps it means that she is around 7th, 8th or 9th percentile?
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