Swollen/red danios HELP!

[Jbaize]

I have a 20 gallon tank with 6 zebra/leopard danios one has always been pretty fat starting a month or two after I got them (jaunuary 2022) recently I noticed she was even bigger and has some red parts on the rear abdomen I don't know what it is any guidance is appreciated

Blurry pictures but its all in could get

 

[Kyanite14]

Is she eating and pooping normally? Perhaps she’s egg bound, in which case you can either try to induce her to lay eggs or reabsorb them. I would separate her for a bit to see if maybe she is too stressed from tank mates to spawn. If she isn't eating it could be dropsy. If her scales are pineconing dropsy is probably the cause.