Lethargic Australorp won't get off nesting box

[DrTheMomm]

One of my Lorps has spent the day sitting on a nesting box. She hasn't laid an egg; she just sits there. There's no blood or anything noticeable, other than she seems lethargic. When the other girls left for their evening stroll around the yard, she stayed in the nesting box. Should I be worried? I am.

 

[BarnyardChaos]

Is it possible she's just going broody? My Australorps are all VERY broody hens. Does she fluff up and growl when you reach into the box?

 

[DrTheMomm]

Yes! That's what I was wondering. This is my first flock, so I haven't had experience with broodiness, but that's exactly what I was wondering. She didn't want me to mess with her and in fact got very annoyed when I did. But I pulled her out of the nesting box and set her down outside the run. She immediately started scratching and pecking. Her comb is bright red and I couldn't find anything around her vent, so she looks healthy, just angry. I'll keep my eye on her. Thanks for your help.