I let my broody hens raise the chicks with the flock from Day 1. My rooster leaves the chicks alone or may occasionally help Mama take care of them. For the most part the other hens leave them alone as long as the chicks do not invade their personal space. If the chicks invade the hens' personal space they might get pecked and sent back to Mama. Occasionally a hen will be more aggressive so Mama whips butt. Some people do have problems with other flock members but you have 1,000 square feet of room. That gives Mama a lot of room to work in. I think that room is important.
Some people do keep the broody and chicks separated for a few days, a few weeks, or even longer. I've had a couple of different broody hens wean their chicks at three weeks, leave them alone to deal with the flock. I've had some broody hens take care of their chicks until well over 2 months. You never know when she will wean them. Mine have been OK with the rest of the flock when she did wean them.
We all have different set-ups, flocks, and situations. What works for one does not always work for another. I want Mama to take care of integration for me. I'm not keeping them separated so long that the hen has to be integrated back into the flock and I have to integrate the chicks. To me it is so much easier of I let Mama handle that.