Heres a link to look at on here, there is pictures of what it would look like inside her if this is what she has.
https://www.backyardchickens.com/t/565084/egg-yolk-peritonitis-prevention-or-management/0_100
https://www.backyardchickens.com/t/565084/egg-yolk-peritonitis-prevention-or-management/0_100