I agree with Donrae. It sounds hormonal and maybe broody behavior. I've had hens that acted somewhat broody but never really kicked over into full broody mode. I've had them behave that way for a couple of weeks before they decided one way or the other. If it is broody behavior, she will either go full blast broody or return to normal.
Some possible broody behaviors are that she may puff up and growl at you if you approach her nest. She may get pretty defensive and peck you if you reach in. When on the nest, she may sort of flatten herself and look like she has zoned out. She will often give a regular pucking sound when she is off the nest and walk around fluffed up. Not all do all this but these are pretty typical behaviors.
My test for a broody hen to see if she deserves eggs to hatch is that she has to spend two consecutive nights on the nest instead of roosting in her normal spot. If she is still laying eggs, she is not there yet. A hen stops laying eggs when she flips to full broody mode. She stays on the nest practically 24/7, maybe leaving the nest once or twice a day to eat, drink, and go poop. Since she has been holding it all day, when she goes poop it is normally a pretty big stinky event.
If she does go broody, you should either break her from being broody or find her fertile eggs to hatch. If she goes full mode broody she can stay that way for months.