You may not feel an egg, she may have laid internally or perhaps she has EYP or something else going on.
I'm sorry she's not doing any better. If you wish to find out why she has declined and you lose her, refrigerate the body and send it to your state lab for necropsy. If that's not...
Does she have any lice or mites?
I'd work on her drinking, electrolytes or a bit of sugar water can sometimes get them interested.
If she's hunched and hasn't been laying, then I'd start her on Extra Calcium for 3-5 days.
You can find Calcium Citrate with D3 in the vitamin aisle of stores...