I have a broody (a buff orpington) as we speak.
We plan on giving her hatchery chicks tomorrow when they come in, instead of the eggs she has been setting on.
As a result, we gave her 5 marked eggs three and a half weeks ago, and our plan was to change those eggs out once a week.
But she -- in conspiracy with the other hens -- had other ideas.
Some of the other hens will lay right on top of her, so she can have their eggs too. And that little girl has even moved eggs laid in the nest next to her into her own nest to set on.
We have to go in there about once every day to remove the "unauthorized" eggs from her nest. (Boy, does she snarl at us when we do that! LOL)
But by allowing her 5 "authorized" eggs and then changing them out once a week, she THINKS she is bringing little chicks into the world, when in reality, we have some chicks on the way that we are going to substitute for the eggs come tomorrow night....
BTW, it probably is best to relocate your broody while she is brooding. However, we did not do that until last night -- only two nights before she gets the live little chicks -- because last time we relocated her, she was so stressed out that she suffered three weeks of chronic diarrhea, and we were forced to chick-nap her babies from her because of fear of her passing a disease on to them. It turned out that she was not sick at all, just stressed out by the move away from the other birds. As soon as she was placed back into quarters where she could see and hear the other chicks, her diarrhea problems dried up, and now she lives with the others again -- disease free.