What is she doing or not doing? Does she want to eat?
The treatment for lead poisoning was calcium EDTA in an injectable form. Once I saw that I realized I had it in pill form for metal detox after Lyme treatment. For a few days after I sprinkled a couple of those on the treat trays every day. I figure if it works that way for people then it should work to some degree for chickens and would hopefully at least help lower any lead issues in my group.
I asked and the lead overload can cause neurological issues as well as internal swelling which could cause them to not want to eat. My hen wanted to eat but just wouldn't. I sent her for a necropsy and she had a bunch of tumors internally.