I was wondering if this is Bumblefoot? My hen started limping yesterday but there’s no “black scab”? I took a pic of both feet but you can see the one is swollen.
It could be the early stages of bumblefoot or infection of the foot. It does look irritated.
Inspect the little dot that I have circled, she may have poked her foot on something.
If possible, get someone to hold her and get more photos that are clear, I know it's almost impossible to hold one yourself and snap photos, just when you think they are holding still, nope.
I'd try giving the foot a soak in a warm epsom salts bath. Dry the foot, then apply a dot of triple antibiotic ointment to the foot pad. Apply a tiny square of nonstick pad, then wrap the foot. Coban/Vetwrap/Sportswrap works very well for wrapping. Check the foot daily and repeat the soaking/ointment/wrap. See if the swelling goes down and the foot improves over a few days. If it gets worse, swells, has an odor, etc. then stop the treatment.
If she's in a coop/run that stays relatively dry, then I'd let her with her flock, keeping the foot wrapped.