At our coop:
they just set in one of the open boxes and dare any of the others to bother her
You do have to mark the eggs under her and check daily because other hens will lay in her nest while she takes her daily walk. She will likely bite you when you check them. Get over it-- it usually doesn't draw blood. ( Hence the expression: Scarce as hen's teeth.)
If the nest is high, plan on fencing her in on the 20th to 23rd day so an early hatcher doesn't get brave and jump out. Provide food and water in those cute little chick feeders/waterers. Mamahen will take them out when she is ready and they will follow and jump enormous distances at her encouragement.
Now... my question: How does the mamahen expect those week old chicks to follow her up to the high roost every night? We never said they were bright creatures. We usually keep a butterfly net handy to scoop them up and add them to the roost under her.