My favourite hen died last month leaving us with 3 chickens. One is a bantam mille fleur cochin. She isn't much into laying eggs, but she is always happy to sit on the other girls' eggs. The other two are standard Americaunas. All three recently turned 2. I would really like to add another chicken, maaaaaybe two. Could I add a 2 month old pullet to the group? Would adding two 2 month pullets work better?