Nichrome, the hen will look sick. Lethargic, not eating, drinking. She may wattle around like a penguin, moving slowly. She won't be pooping, and if she is, it will be diarrhea. Many times if you inspect the hen you can feel the stuck egg. Sometimes it is right there at the vent. If you apply...
Try soaking her lower half in a warm Epsom salt bath. Many times the Epsom helps with blood flow and extract the egg. Keep her soaking for about 15 mins. You will have to hold her in the water. Keep us posted.