I do this two different ways. Often I let the hen hatch with the flock and bring them off the nest when she is ready. She knows better than I do when the hatch is over. I put food and water on the coop floor where the chicks can get to them and eave the rest to her.
When my coop is pretty crowded, I let her bring the hatch off the nest when she is ready, then put them in a predator-proof shelter inside my electric netting. I leave them locked in there for usually two or sometimes three nights with food and water. This way the hen will take them back to that shelter at night instead of into the crowded coop.
I raise mine for meat. I time the hatches so the overcrowding is no longer a problem when it's time for the chicks to move into the main coop or my grow-out coop. We all have different goals and set-ups, I don't know which might work best for you, but both these methods work quite well for me.
Good luck!
