I agree with above post.
What your doing isn’t working. Take her to an avian vet.
They Can test her culture for the right bacteria and give her the right antibiotic with the correct dosage. You may have developed a resistant bacteria.
We caught a feral peahen. She stayed for a day-roosted in our tree overnight & then off to another neighbor. Used a fishing landing net-caught when she had just lifted off to fly away.
I agree-it could be something environmental.
Could her immune system be weak to the infection. Usually if an antibiotic works but the infection reoccurs then a longer treatment period or different antibiotic is in order.
Not one at a time?
Well, I only have 2 americauna's. I ordered 2. One died. Her replacement came 2 weeks later. Now the older looks like a raptor & the younger is 1/8 the size. They are in same brooder w/the hardware cloth separating them. They talk together & cry for the other if I only have...