Bumblefoot, judging by that sore on her foot. It doesn’t look too advanced so if treated now, she should be perfectly fine. Treatment as follows:
1) Bathe feet in bath with epsom salts
2) Dry feet well (blow drier on coolest setting if possible)
3) Apply tea tree and honey directly to scab and area surrounding scab
4) Bandage carefully with gauze and Vetwrap, so that the bandages won’t come off
5) Bathe feet and change bandages after 24 hours, again 3 days after that, and again 4 days after that.
Repeat this cycle if it comes back/doesn’t go away. If she or other chooks try to peck bandages of smear a little mustard on them (they HATE it). Let me know if you have any issues or questions, I’ve treated this more times than I can count on several chickens
Best of luck!