I caught her within moments of it happening and assessed the damage. It didn't look fatal and I took the chick and rinsed her under warm water until the blood was washed away and wrapped her in a washcloth to help her dry. I let her back under the heat plate with the other chicks and monitored her.
I just flipped her over to look at her bottom just a few hours after the incident and her fluff was matted to her bottom with a gluey, crusty substance. I rinsed her again and dried her.
Just now I noticed the gluey stuff is there again. I'm posting pictures of it, hopefully y'all can tell me if I need to continue to rinse this stuff off or if it is there for a reason to help her heal.