i would say make her do the cream for a month bacause havin belly button periced you HAVE to look after it or else it will get severly infected and its not good and she will have to end up taking it out i got mine done when i was just turning 14 so if she is like just turned 13e then thats a little young but ya make sure she staus on top of her cream or shes not gonnna look after her ring, and who did her freinds belly button no peircings done properly bleed only the ones that are done by a unexperienced person like a freind, i would see if the other girls mom knows she got her belly button peirced