laying yolks but no shell

Poor hen. It sounds like she had trouble passing an egg (called egg bound) and it broke inside her. Or perhaps she is passing an egg with out a shell. I think the first possibility is more likely. She may be very uncomfortable because she still had egg shell stuck in her vent. People typically recommend soaking the egg bound hen in some warm water to help her pass the egg, which relaxes the muscles of the vent. vegetable oil can be applied to the vent to help. Sometimes the vent requires flushing with a syringe or dropper of warm water and a little vinegar.