Anywhere from a couple hours to 24, when they start peeping, it means it pipped a hole in their aircell at the fat end of the egg and is breathing air for the first time. The next step is it will peck a hole in the outer shell and breath fresh air! After it rests, it will start "zipping" in a circle until it can pop the top off the egg off like a lid. I love incubating eggs in a glass topped incubator so you can watch while they hatch
When all babies hatch I would personally suggest moving mommy and babies to a separate area, as some roosters and hens can get aggressive with new chicks and hurt them, or worse. When your chicks are several weeks old, you can decide if you think they're all ready to be integrated.
I have mean hens, so I waited to integrate until my chicks were two months old. But if you have docile chickens then you might have no issue.