Yes, DE--sprinkle on her (I bought a salt/grated cheese shaker at Dollar Tree and put DE in it and I keep it handy to shake on their backs--especially if their dust bath is getting low or inoperable due to weather). I also made a small batch of coconut oil and mixed in DE to rub on their shanks/feet/toes/fleshy parts--that's helped keep off any mites for several days.
Also, have you witnessed her molt yet? One of our 3 scraggly hens just molted for the first time and she now looks like the queen of England--whoa nellie she looked 100x worse than usual during molt--we're all simply amazed at how transformational molt is.