Is every

loose from that bird? Do you notice her drinking more than the rest? Does she have

y butt feathers? Do they get kitchen scraps? (Mine do and if I give them too many I have one girl that gets a horrible behind from it)
When I have chicks with

y butt I give them some oatmeal to bind things up a bit. It's a temporary fix but you could try it. If she seems to otherwise be eating normal I'd probably just keep a close eye. Being a newbie though do remember that chickens will hide an illness until they can't any longer. They will pretend to eat so the others won't notice something wrong. So you really need to watch. I learned that lesson the hard way so just passing it along.