Congrats on the hatches! Love the pictures Schmoos and Dawnh.
I just came back from checking on my broody (day 20) and I'm 90% sure I heard tapping under her. That hen has not changed position on the nest box in two days. She looks exhausted. I put food and water directly in front of where her head is last night and she ate the food, at least. My fingers are crossed that I get some chicks soon.
As far as introducing the chicks, for both of my previous hatches, the chicks were hatched in the main coop (one in a dog cage inside the coop and another in a nest box) and around the other chickens from the beginning. It must depend on your flock, but I didn't have problems with the other hens harassing the chicks. My rooster was extremely protective of the chicks from day 1, and I think that helped. I'm glad it worked out, because it was great to be able to keep them together, not have my broody lose her status in the flock, and not have to go through a process of integrating young strange chickens into the main flock.
I think if the broody and chicks has been in a separate brooding area, I would wait several weeks. The broody is going to be picked on by the rest of the flock and in no position to protect her chicks effectively.