Hi All, 4 months ago I bought 3 blue Australorp pullets. At the time their combs were small and lightly coloured. In recent weeks two of the hens have developed beautiful large red combs and I got our fist egg yesterday! However the third hen has hardly developed, her comb is still very small. She seems active and no other obvious reasons for concern. But obviously she has had enough time and been exposed to the right diet to put on condition. Is there anything else I should check? I am new to chickens so any help appreciated. Many thanks.