It's not unusual for one to be pecked at occasionally. Looks like her wattle may have been pinched. The peck mark on the comb, I would keep watch on that, but it will probably dry up and heal o.k.
I would check her crop to make sure it's empty in the morning before she eats/drinks. Let her...
Welcome To BYC!
I'm sorry you're having trouble.
Can you post some photos of your pullets, their housing, some of Agnes and her foot too?
What do you feed including treats?
How large is your coop?
Hopefully with a little more information and photos we can offer some suggestions.