I have a Dominique hen that is at least a year old and NO eggs,Nothing, NADA! Is it possible for a hen to be sterile. Her sister has laid and molted and is laying again. The rooster is doing the rooster thing with her, she has a beet red and plump comb and she sits in a nesting box but has never laid a single egg. Could she be older then I think and done with laying? I am just confused. Anybody have any advice or suggestions?