corgan-i did what you suggested, and I still say she's NN....the closest I've seen to her being topless is this link from above
http://www.teenqueens.net/galleries/mymyisabella.html
otherwise, the pics are no more revealing than Maxim or Stuff, which means NN. She's still hot, but nude means clearly seeing the nipple-tastefully covering boobs with hands, clothing etc=NN