Yeah, she's the queen of the run at the moment. They tend to hang out under the coop during the heat of the day (I have a fan blowing through there to keep the air moving since it's been ridiculously hot), but they all head into the coop several times a day and spend time in the nesting box.
I'm hoping they'll instinctively know what to do, but the fake egg suggestion is a great idea. I'll see if I can find some. Joann Fabrics closed here, so I'll have to find another craft store that may carry them.
Golf and ping pong balls work great as well, if you’re able to find those more easily