She doesn't like to be held but I'll try to grab her off the roost tonight. I'm not over there all the time, just for my volunteer duties.Watch her some more. Look for her to peck her foot or leg. When she does that, it will tell you exactly where her problem is.
My guess is she has some gunk on her foot. Or bumblefoot, which is a bacterial infection and it hurts. Examine the feet, tops and bottoms. Examine her legs for swelling. Compare the two. Perhaps the right leg is thicker at some point, indicating arthritis or some other bone disorder.
All good suggestions. In addition to examining her legs/feet, I would check her crop as well.There is a hen at the farm I volunteer at that walks/runs really strange. She always does this. She looks to be a welsummer, but I'm not sure of age. I'll attach a video: