My hen has a limp and a bump
Can you post photos of the bird and the foot or a video of her actions?
Keep her isolated/quarantined so you can observe her for any signs of respiratory illness, diseases, worms or parasites. Practicing bio-security between her and any existing flock(s) you may have.
Since she was "labeled" with a bad leg, it could be that she has been like this for some time. An injury or even some illnesses can cause them have a limp or be lame.
The bump/lump is hard to see, but I don't see any bumblefoot. You can soak her feet in a warm epsom salt bath to see if it helps any and the bag balm won't hurt.
Watch for signs of inflammation, redness, swelling or oozing, but it doesn't really look "angry" either.
Can you get a better picture of her and her wattles and comb?