Those shell less eggs can be very hard to pass, there is nothing for the muscles to push against. That alone can make them feel very unwell. The calcium will also help with contractions. If you see evidence that one has ruptured inside her, passing runny yolk or whites, then that can be more concerning and lead to infection.
She was lowest in pecking order and none of them liked her. So, currently, the pecking order has to be re-established. She could be stressed AND mourning now.
