Can you take a flash light and look inside her beak to visualize her tongue and look for anything wrapped around the tongue, or any yellow or gunky patches inside her beak and throat? Also, she needs to drink more medicated water. Eating watermelon will get more fluids into her, but no medicine. If you lose her or decide to put her down, I would get a necropsy on her by your state vet. Here is a list of state vets:
https://www.metzerfarms.com/PoultryLabs.cfm
https://www.metzerfarms.com/PoultryLabs.cfm