posted 9 years ago
If she's only sitting on one, and you don't have a box you can pop over her, I'd be inclined to try something like this.
Make her a 'safe space' somewhere, preferably secluded and dark. Make her a cozy nest then move her *and* her egg to it, ideally during the hours of darkness so she's more likely to accept the move. She might move off the egg for a while, and it might end up no longer viable if it cools down too much, but it's only one so don't panic. In the morning, if she's still sitting tight, give her a load more fertile eggs to sit on, and remove the 'one'. If you left it with her, even if did hatch it would do so a day or two before the other eggs, and she'd likely abandon those eggs to take care of the one chick, so it's probably better to sacrifice that egg and give her a better chance with the others. If the move makes her come off the nest completely, again it's only one egg you've lost. She'll then likely lay another round of eggs and go broody again, by which time you might have persuaded her to lay in a better place where you can protect her.