A couple of days my DD (5) was hurt by another girl at school who twisted her nipple so much that it caused grazing/bleeding. It is now still sore with a sort of scab forming over half of it. Quite apart from being pretty unhappy that this has happened to her, I've started getting worried that this may have caused some damage to the tissue underneath (obviously completely unformed because she is such a young child). Can someone talk me down from my worry about this?