Well I've tried and the hen flipped. She knocked over the eggs, crushed one and knocked over water and food. There is only one chick and I put the water and food nearby. They are in like a tiny mini coop/ brooder. The chick usually stays under mom or near the food which is right by her. So I'm gonna leave the chick for now....
Yes definitely leave the chick with mom.
Hopefully momma will just naturally be sitting with the new chick anyway these first few days...enough to hatch out any more from those in the shells...this is of course the risk when you have delayed egg settings...momma gets distracted with the hatched chicks and is less likely to sit with the eggs.
I can't remember how many days apart the eggs are....if you still have 3 more days left and an incubator...it might be wise to put the eggs in the incubator to finish hatching then attempt to reintroduce the new chicks after they've dried off. Momma will likely accept them quickly, and if you only have one older chick, it shouldn't be a big deterrent to the others from connecting with momma.
Lady of McCamley