Your grandddaughter should contact the office of the Judge Advocate General (JAG), which is the legal services part of the military. JAG lawyers prosecute courts-martial, but they also represent soldiers in courts-martial and other disciplinary proceedings. I'd hope that as in the civilian justice system, there is a way she can appeal this decision and get a hearing, to explain her side of the story; whatever recourse she has, the JAG attorney will know what it is, and the services are free.