hen brooding all of a sudden

[1chickimama]

My girls were already laying when I bought them 4 months ago.I have 7 hens and have been getting 4-6 eggs daily. They have 5 boxes between them, however I find the majority of the eggs in this one box. For the past 2 days one of my hens has not come off of the box. Yesterday I had to reach under her and collect the eggs. She never moved.
I was worried about her and after dark, I went to the coop to check if she was inside. She was still in the box. The box is outside the coop. She was there all day today. I only got 1 egg today and it was in the middle of the pen. That's seems a little weird to me. I guess she is disrupting the other girls from staying in that box. What can I do or should I do anything at all

 

[sourland]

She has gone broody - either you can give her some fertile eggs, foster some chicks, or break her broodiness by caging her away from the nest site.

 

[1chickimama]

I have 5 baby chicks that have just finished fethering out and last night was their first night in their pen (seperate from the 7 big girls) Would it be safe to put my brooder in with the small girls? Shirley is the runt and she only weights 7 ounces, the 4 others are about 4-5 times her size. There is no nest in the little ones pen.