Is it possible that it just got buried in the sphagnum moss or something? I know my snakes will push around their shed skin to get it out of the way if I don't remove it. Maybe she pushed it underneath something in the cage? I've never heard of a snake eating a shed, and I doubt that she was that hungry from missing 2 meals (2 weeks) that she'd feel the need to eat her skin, but you never know. Weird things happen.