That does not seem to be a problem with chickens.Do you have to worry about them getting sick from the older chickens? Our girls are healthy, or at least they seem healthy to me. I know next to nothing about the chicken immune system or anything like that, so I wasn't sure if they needed to be in a brooder when they were babies for health reasons as well.
Just keep the chicks dry, and at the correct temperature, and they should be fine.
They can go straight into a brooder in the coop, as long as the brooder provides what they need:Do you have to do anything special to brood the chicks in the coop? We will be getting day old chicks. Could they go straight into a brooder in the coop? Or is it better to wait a couple weeks?
--protection from weather (rain, snow, wind, too much sun)
--protection from predators (including cats, adult chickens, etc.)
--correct temperature (one place about 95-100 degrees so the chicks can get warm any time they want, and lots of cool space so they can move away from the heat when they choose)
--water and food (chick starter)