Have Bird Questions? Ask a Bird Specialist.
Hi this is Dr. Michelle. You might look at her vent to see if it is pushed out like she might be eggbound, which means an egg is stuck. If this is a young bird, or she has been laying soft eggs, she may be low on calcium and the eggs are not forming properly. That would be the first thing I would check. If not eggbound, then separate her, offer heat support such as a heatlamp and see how she responds to that. How old is this hen?
Is your hen still sick? eating and drinking? do you have a rooster that may have injured her?