There are a lot of different signs that a hen might be broody. I’ve had hens show all of them but it was false. She never did go all the way into full broody mode. The way I tell if a hen is broody enough to be trusted with hatching eggs is that she has to spend two consecutive nights on the nest instead of in her normal rooting place. That test, two consecutive nights, has always worked for me. If you have a broody hen, you have a few options. You can do nothing. The hen has built up a fat reserve to live on while being broody. That’s why they don’t have to eat and drink a lot. They will lose a lot of weight while broody, but that is pretty much just excess fat stored for that reason. But some hens will remain broody after that reserve is used up. Personally I would never go this route. I either break them or give them eggs or chicks. They are also not laying eggs while they are broody. Another option is to get fertile eggs for her to hatch. If you want to go this route, we can give you some suggestions on how to find fertile eggs. Or you can get very young chicks for her to raise and give them to her. Another option is to break her from being broody. I use a cage with a wire floor, just leave her in there with food and water and no nest for a few days. That’s always worked for me. Here’s a thread about breaking a broody that might help. https://www.backyardchickens.com/forum/viewtopic.php?pid=2176186#p2176186 I don’t know what is going on with your Buff. I assume you have checked under the other hen to see if there are any eggs there. Some broodies won’t allow other hens to lay in their nest, though most are willing to share. It’s possible the Buff is hiding a nest somewhere. If it has just been a day or two, it may just be a cycle she’s going through. It’s also possible something is getting the eggs. If that hen is truly broody, that may have upset the dynamics of their little flock to throw her off laying for a few days. There are just so many different possibilities it’s hard to say. Good luck.