I don't know about the school or how to handle them in your situation bUT thought I'd chime in because I had the exact same problem in school and now in my everyday life and have since grade school. Is she a perfectionist or procrastinator in other areas at all?
She might be bored, I certainly was, but the thing about that kind of behavior, is that it's addictive. You procrastinate in whatever way, and then hurry to do things last minute, creating a sense of anxiety. Then you (hopefully) finish the put off task, relieving the anxiety. The feeling of relief is more rewarding than a rewarding feeling would be without the anxiety, so you proceed that way the next time. Over time you find yourself unable to feel motivated in any other context.
If she's not being appropriately challenged, changing the difficulty could help, but I think there's a skill set you learn that helps with that If you wait till older to learn those skills it gets much harder. So if I start seeing signs of a similar problem with my ds anytime soon, I know that I would have to do something or get help for him sooner rather than later. Maybe the school could help. Or if it's framed as a psycholocal issue as opposed to an educational one, maybe health insurance would pay for a therapist to work through it?
