It appears from the photo that your little one could have a very, very painful case of scaly leg mites. The best thing to do is give her a nice long soak (30 minutes) in a warm basin of Epsom salt. This loosens the crust, then you can take a soft brush and gently scrub most of them away. Then give her feet and legs a good slathering of castor oil, working it into the scales. You need to repeat all this each week until you see the scales are returning to normal.
I have a very old hen (going on age ten) who is susceptible to leg mites because of her age. I found that an excellent cure for leg mites is spinosad. It can be purchased under the brand Elector PSP. It's very pricey but concentrated so a bottle lasts for years.
What I do is make a warm water soak with it that covers the feet and legs all the way up. My hen spends about ten minutes in the spinosad soak. This gets rid of the mites, and the improvement to her scales is just short of spectacular. It's long lasting, and the scales continue to return to normal and the mites don't return.
If you can't find flexibility in your budget for Elector, then go to the pharmacy and pick up a bottle of children's lice shampoo for a fraction of the price. Make sure it says spinosad is in the active ingredients.