Chicken down! Please help!

Hi, I am pretty new to raising chickens (8 months into it) they are "pets" and the bonus is that they lay eggs! One of my1 1/2 yr old hens has been a little down for a few days. She ekes her head tuckind-in like a turtle, and her tail is pointed down instead of her usual perky self , head and tail up!!
She eats, drinks, not too much but still doing both. Her belly between her legs is very swollen. I thought she may have had an impacted egg so, I did it..I lubricated my finger at the instruction of a chicken book, and stuck it up her bum and gently tried to feel if there was something hard like an egg...I went in about 2 inches and felt nothing except poop. I think it is her intestines that are swollen. yesterday, she was lying down most of the day, "pumping her tail" as if she was going to lay an egg.(she did not, and is still "pumping" her tail).
aha I have tried thus far:
1. I held her in a leg-to-tail- deep warm epsom water bath and rinsed her off. she seemed to like that so I'll try it again today.
2. been giving a slight amount of apple cider vinegar in her water (1/8 tsp to 4 oz water)
3. tried cottage cheese
4.leaving a variety of food for her to keep eating: baby greens like beet, kale, spinach, grit and regular pellets some meal worms.

I'll check again today if there is an impacted egg, but short of that, I don't know what to do. I have her inside to keep her warm (it's still pretty cold here in Maine), her mates are back in the chicken house I know she would probably rather be in stead of a 18" X 18" cage inside.

Please help! where she is swollen, is her lower belly, quite reddish-pink in that area, between her legs, just almost up to her vent. Poor thing!
Thanks Danielle

 

She is still eating...a little of this a little of that. doesn't want berries which is unusual for her. she eats just a few greens now and then, (someone suggested half of a cooked egg mixed with 1 tsp of yogurt and water with her normal (organic) feed. She eats a little of that. Loves her dried meal worms, so I try to mix those in really well both in food and drop them in her water so she gets a little food and water with the worms. She has been drinking s good amount of water (I mixed in 1/8 tsp of organic, apple cider vinegar to the 4 oz of water for her). She lies down often..She keeps "pumping her tail" like wanting to lay an egg...all day....all night. her lower belly between her legs and up to her vent is quite swollen-about the size of a softball and irritated red, and feels hot to the touch.the feathers there are very sparse, like molting or something.. the belly also, seems a little more firm that the past days, she does not like it touched.Once in awhile, it seems like she stumbles, but I think it is because she is in a 2' x2' cage for now and she stumbles when she tries to turn around.
I will give her another warm belly-bath, with epsom salt, maybe with some lavender oil and chamomile. I will try to check daily to see if i can feel a stuck egg...Her spirit seems pretty good, it seems like she is keeping her head (and tail) up most of the time whereas before, her head was tucked in like a turtle and her tail was drooped down. She still prunes herself-so, there are good signs, but the belly does not seem like it is getting better. please keep in touch with any other suggestions. thank you! Danielle

 

Queen Misha, is there anything I can do for her to make her well, or will I have to "put her down"? if she has what you suspect a "long term reproductive issue, such as egg yolk peritonitis or an ovarian cancer/infection". How can I tell if she has any of these other issues (other than a stuck egg....I know How to find that one out !) Thank you, Danielle
It throws e off because her spirit is good for having this health issue. I am sure it is uncomfortable for her.