My Brahma is limping

My sweet Fern started limping a couple of days ago, it wasn’t that noticeable at first but today when I went to let them out of the run she was lagging behind so i called her and she was hopping on one foot so I picked her up and brought her inside to investigate and I don’t see any obvious signs of injury or infection. At the moment I have her in a tub filled with a couple of inches of warm water and epsom salt and she seems super content. She freaked out (of course) when I grabbed her with a towel and flipped her upside down to look at her feet and take pictures for you guys… but if someone could help that would be greatly appreciated. I love this girl so much.