I have a broody banty that wants to set eggs. I've decided I'm going to go ahead an let her but is it too cold at night or will she keep them warm enough? and will she be able to keep the chicks warm enough if/when they do hatch? We are dipping down into the upper 30's at night but the coop does have a heat lamp in it. I only let her have 4 eggs and I'm not sure how many will even be fertile.