Oh I see.
Looks like she may have the start of a pressure sore on her joint.
How does she sleep at night? Does she lay on that leg?
I'm not sure if it would help, but you could try putting her in sling a few times throughout the day to get her up off/take pressure off the joint to see if that helps.
If she's sleeping on the leg, then you may want to make sure the bedding is good and dry, clean and soft.
She would have to monitored while in the sling to see if she's agreeable - some birds can't tolerate the confinement. You may have to play around with the design to ensure the sling doesn't pull or press her leg the wrong way. It's just a thought for you to consider. You may find it doesn't help.
Below is a short video of a sling, but if you google search chicken sling images, you will see a lot of ideas.
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