Did you check her temperature? That may calm your worries knowing she doesn't have a fever and also tell you if perhaps you should consider having her treated if she does have a fever. Unfortunately with egg peritonitis she can keep laying internally while your trying to treat her infection making it worse. kinda like taking one step forward then two steps back kinda thing. There is a drug out there called Lupron which is a hormone that will stop her ovary from releasing eggs for a few weeks so she can recover from the infection. I have not tried this drug yet for my girls, my vet says its very expensive ($400 a vile). It is also possible to have a chicken spayed but it is a bit tricky because the ovary can be hard to access. I've heard you need to have a good vet who knows what they're doing, they have to remove every single follicle or she can still ovulate into her abdomen. Also there is drug called meloxicam that can help with the swelling (it's a NSAID ). And of course she'll need an antibiotic. I have two hens who have been sick with it for a week now and this is the first time I've had to deal with egg yolk peritonitis but I have been reading about it as much as I possibly can. my girls are on 2 different antibiotics and a iron supplement and I still can't get their fevers down. They do seem do be feeling better. I let them out in the Sun today with the rest of my flock and they spent the day digging in the dirt, eating bugs, taking dust baths and sunbathing! It was a very good day after a very stressful week. if one things for sure it's that chickens are tuff little creatures.