Looks to me like it might be fowl pox or possibly a fungal/viral wart.
Sometimes with fowl pox there can be further growths on the comb or skin, it will run its course and they will fall off. However if they are still there in a couple of weeks you might need some anti fungal medication ?
Betadine might be something to try. Fowl pox is carried by mosquitoes so it's not something we see much in the UK but maybe they are about where you are ?
It looks to me like another chicken could have pecked her there and it's started to abscess a bit. However, looking at her comb and wattles, I see some scabby places, so it may also be fowl pox. Check out your other chicken wattles and combs and see if they also have these scabby areas.