Thank you, and everyone on this thread, for your help this week. I learned a lot that will help me with my next hatch. I recandled the eggs last night (day 25) and, unfortunately, could tell they were dead. I opened them and they didn't smell bad, but the yolk and white were all scrambled together. What I was seeing while candling at the pointy end was just the yolk-shake blocking the light. I should have learned more about how to properly candle before starting this, but so many u-tube videos just show someone with a flashlight and an egg and "look at this." I've now learned to look for different things at different stages, so I won't have the hen brood for a month when there's no need to go that long.
Thank you to everyone for your support and encouragement and your knowledge. Hopefully next time I have a broody hen I will have better news.