One chicken gone missing ...

... thats what I thought when I went to lock them up for the night. I always count them when they sit on the stick; 1, 2, 3, 4, 5, 6, 7, 8, .... !!! Where is the 9th one !!! So I looked outside and she was not there! One brown one was missing! Then I looked into the nest boxes and there she was sitting on the eggs :)) She became broody :)) how great is that! Now I have to research what to do so the other hens don't lay new eggs every day into this same nest when she is eating. I think I might separate her into the newly built cage within the same coop. I wonder how many eggs can she brood?