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...
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...