I suspect you are in somewhat uncharted territory here, since most members allow their birds' feet to auto-amputate instead of paying to take the surgical route. I briefly searched BYC to locate a surgical amputation thread, but didn't find anything to help answer your questions. However, you should find some info re surgical amputation on various parrot forums. I will link one site to get you started, but there are others if you google "bird surgical amputate foot" or something similiar. .I am HOPEFUL she will just get on with her stump because it would be less maintenance. However if she needs protection it’s an option as is wrapping the end with vet wrap - just curious how it will heal - when a human leg is amputated they cover the end with skin. But this was just left open with exposed muscle
https://www.justanswer.com/bird-vet/gzxmz-conure-needs-foot-amputated-result.html
Every case is unique though, and the more posts you make updating Polly's recovery progress, the more you will help future others who find this thread because they face a similiar situation.
Large fowl bird amputees usually need wrapping and padding to protect the stump(s), while smaller birds often do not. Polly is currently a wee chick that will eventually grow into a large fowl chicken, so you are in somewhat uncharted territiory there too.
Are you still giving her oral antibiotics?.
