Have you tried soaking her in some warm water? If there is something stuck in her vent she might be able to push it out when her body is relaxed in warmth.
Have you seen any blood on her eggs, or have you cracked one of her eggs open to see if there is blood inside of it?
Do you keep any species of waterfowl with your chickens, including ducks and geese? If waterfowl mates with a landfowl hen, they will kill the hen due to difference in organs.