It can present some problems, I have tried it. They may scrap and the chicks can suffer harm from bodily damage or get lost in the melees. I use seperate pens for each hen w. chicks unless I pull them and use a brooder. Left to free range can be beneficial but the risk of loss of chicks is real, the most fit will make it but that might not be the ones most desirable for your needs?

Not sure if you want to do this, but you could just let one hen mother all the chicks that hatch, that way you only have one mother hen, and don't have to find a separate place for the babies and other hen. If you put the chicks under the 'main hen' at night, she won't know the difference by morning.

Thanks, for the imput. I have discovered a Barred Rock setting in the potting shed so that makes three. Each have 12 eggs so it may get crowed in a few weeks. I've spent a good deal of time dividing the existing chicken yard this week. I have safe and secure lodging for the first two. Now I have about 2 1/2 weeks to stretch some netting around another area for the third. I have homes for all of these. My Vet has 6 kids all dying to raise chickens.
Thanks again for your imput..