The rough spots are probably just stuck shed. Her humidity needs to be kept nice and high. They will replace her with another snake, make $500 more, and more snakes will continue to be underfed and undershed. /shun
Now that the shunning is over with (haha), she doesn't look emaciated to me, just thin. You might want to put her in a warm, wet pillowcase for about 20 minutes a day for a few days to work on the loose stuck pieces. Keep her conditions just right, keep her in quarantine until you can make sure she has no health problems or mites (so that other person in your picture holding her snake needs to watch for the same), and quit buying snakes from pet stores.
Good luck!