Insufficient Postage

So I confronted a student about her constant doodling in class and her response (as matter of fact as all get out) was, “But I’m designing my tramp stamp.”

Where does one start?

She’s seventeen; she’s designing her own, uh, ‘tramp stamp’ and she sees it as an adequate reason not to be doing school work. Do I start with tramp-dom might not be the wisest decision? It’s certainly more important than study skills, but how do I get that message through to one who is so enthusiastic about the whole thing that she wants to create a logo?