I bought four pullets at the beginning of last September. They were all "supposedly" 3 months old. Three out of the four have grown and developed nicely and begun to bless me with eggs, however the fourth, who is also at the bottom of the pecking order, has not even developed a comb yet, let alone lay any eggs. Is this a common thing or will she just continue to be my eggless friend? She is such a sweetie too!