Fowl pox is a viral disease for which there isn't really a direct medication to treat the outbreak.
I just had a sweet baby die in my arms today from fowl pox, it blocked her trachea and caused respiratory failure. She had outbreaks around her eyes, nostrils, and beak. Pretty bad when they get around the face and eyes. Cause blindness, stunted growth, and other illnesses. Your baby has one below her eye. The mother hen is scabbed and will survive. Coconut oil will help the scabs heal.
Lots of decisions for you to make for your flock because it's highly transmissible between birds. Me personally, I let my hens and babies stay together and I have never lost an adult to fowl pox, but I lose quite a few weaker young babies.
I change out their nests and they keep their babies seperate from the flock. Coop cleanliness has helped a little, but I still see outbreaks although they sometimes go away and don't return.