Pgpoultry - u just voiced all my concerns! Those are the things I've been considering. She has not shown any sign of being interested in going broody and I originally removed the egg from beneath her and she kicked up a storm! She wentbaround the run calling non stop and the roo went right to her but she wouldn't let him help. Finally, since she had never behaved this way, I put the egg back in the nest and her too. She went out to eat, for 20 min straight!, and then went right back to sitting!
Another question, why is she sitting on just one egg? Yesterday was her first day back laying after a day off. She would normally lay five more days. So whynsit now on this one egg?