I think it will be very sad for both the mama hen and the babies to take them away at 4 weeks old. Any chance you can wait until she is ready to wean them?Plenty of room but I won’t be keeping the chicks. I’d want to be selling them from 4 weeks old. I have some friends that will take pullets or cockerels. If she sticks till Saturday I’m going to be buying her a couple of non expensive eggs.