I think that the outfit is cute and appropriate for most school dress codes, so I have to wonder if she was wearing it differently with the skirt hiked up, if the principal was over-reacting too it, or if there is a straight out lie somewhere in the story. I would like to know what the school rules say, it is possible that skirts must hit the top of the knee or lower, in which case, yeah, this skirt might be a little short. That rule might be a little strict, but if that is what the rules are, then the school was in the right.