The school should evaluate for specific learning disability--written expression. If the student has an anxiety disorder that is the primary cause, it would affect other areas of functioning. The school needs to follow the Child Find mandate. If a disability is suspected, they need to assess the student. It is not up to the parents to get outside evals before the school does anything, although in this case they would probably be wise to do that, because the school personnel are going to come to the conclusions that they have already determined rather than doing an unbiased eval.