I would have turned everyone loose, 2 weeks ago. The mama will thump on any bird picking on her baby, so the layers kind of think that they just have to put up with those little ones, and does not discriminate which chicks are hers and which are not.
I see a lot of people keeping their broody and chicks away from the flock until later, but by then, the hormones are waning from the broody hen, and she has to reestablish her pecking order within the flock. Where as, a fresh broody hen is a highly hormone incensed bird...... way to the top of the pecking order, and her chicks are tolorated very well.
My chicks are in the feed dish, in the way of the layers, and they are allowed there. One old red would like to give a peck, but mama is more than willing to peck back.
Mrs K