Hi
@4 Georgia Hens I'm sorry you're girl is not doing well.
Did the vet take an x-ray?
Is there any notable swelling/bloat or feeling of fluid in the abdomen?
Having an egg lodged between the legs? This sounds like an internal laying/reproductive disorder - anytime there is an egg "stuck" that is not good. You can try soaking her in a warm epsom salts bath to see if this will help get things moving. Provide her with vitamins in her water and see that she is drinking well. Make sure she has a source of calcium (oyster shell freed choice). Watch to see that her crop is emptying overnight.
Let us know how she is doing.