She won't start laying again until she's done raising chicks. The time frame varies from one hen to another. Some don't want to ever stop mothering, others figure once the chicks have feathers, they're done. You'll know she's done when she starts roosting again. Then she'll be about ready to resume laying. Meanwhile, she can eat chick starter along with the babies, it won't hurt a thing. She could eat layer pellets now, but it's hard to feed mom one thing, and the chicks something else.
