I agree. If she’s usually to be found sitting in a nesting box, she’s likely got at least a mild case of the broodies. If she does, you should probably break her unless she’s older and you have fertile eggs you’re willing to risk. Pullets are often not ready for the commitment.
If you were to think, “Well, I don’t need the eggs, so let her sit,” then you should consider the nourishment and exercise she’s not getting while she’s sitting on those infertile and/or fake eggs. Unless there are chicks to be hatched, breaking her of her obsession is the compassionate thing to do.
I had one and didn’t know I should break her. She’s still thinner than her breed sisters. A second one, I put with the broilers in their tractor (which I was moving a couple times a day) for a week or so. It worked, but she wasn’t bad and besides that option isn’t going to always be available.
There are all sorts of schemes out there to break broodies. Here’s one that sounds good to me: Put the broody in a wire bottomed cage, up off the ground for several days. You may need to affix some hardware cloth firmly to the bottom so she has a reasonable place for her feet (outside so she doesn’t cut her feet on the edges). Let her out a couple times a day to poop and get some exercise, but watch her and don’t let her sit. When you feel she might be ready, let her out but keep checking on her and put her back if necessary. The theory is that with air, not a warm nest under her belly, she’ll naturally recover from her broodiness.
If that isn’t working, search here for more device. There’s lots of it out here.
