Update/addition to my previous answer.. I generally don't give a hen chicks before she's been sitting at least 2 weeks.. Doing so too soon *may* not allow enough time for the cycle to come full circle.. she may not be ready to leave the nest with them yet.. ALL broody's are individual so your...
She must relieve herself at least once per day. And also eat.. this is normal behavior.
Totally.. I even wait until they're hatched!
I even tuck in (sexed female) feed store chicks at night so she feels them and hears them throughout the night and they learn one another's voice and make that...