User blog comment:Maki Kuronami/Lesson 18: Ruby, why you so bad with faces?/@comment-2006510-20140801013641/@comment-10380701-20140801013921

Cinder enrolled in what, 2 minutes? She still needs to pass the Initiation of whatever school in Haven she is disguised as.

For all we know, she's not a student at all. It's her age that people are determining.