without seeing and more info, I would start with treating for Scaley leg mites, A good product to have around is Permethrin 10, make solution and stand hen in it for 5-10 seconds, you can go ahead and dip her whole body, she will be pest free. I use the stuff to spray everything on the yarn, then dry off excess and put Triple antibiotic ointment or just Vaseline or meosporin over the whole shank og her leg, put it on heavy, it will smother the mites. It could be from Joint infection, how heavy is she, how high is her roost pole. if its been freezing cold, could be frost bite. either way keep some Permethrin 10 around and use it, Great stuff and very safe when used as correctly, has a great instruction booklet with it. 10-15 dollars and it goes a long way. good luck with her
Sonee06, I had a similar problem with a very nice Brazilian/Burmese Hen. Her right leg, including shank and toes became swollen. I administered Penicillin for a week and noticed no change. I eventually had to cull her, as I did not want to run the risk of her condition spreading to the rest of my flock.