Welcome to BYC! :frow
Sorry she is unwell.
Looks more like a pendulous crop.. link for review.. but also it's just one quick possibility..
https://www.backyardchickens.com/articles/how-to-treat-sour-crop-and-impacted-crop-and-how-to-know-which-one-youre-dealing-with.73607/
Water belly is...