We have a flock of 8 (very well loved) hens. We have our "original 4" that are nearly 8 months old and laying well. We added 2 Australorp sisters 4 months ago that are now 6 months old and not yet laying. The last two are 18 month old hens from a person who had too many, so we "rescued" them about 1.5 months ago (healthy and now well integrated). The flock are mixed breed except for the 2 Australorp...which are the birds in question... They are 6 month old sisters. One is maturing well and showing signs of laying (Amelia). The other has been slow in maturing and acts sluggish (Cora). She started standing off more when we introduced the two older hens, so we thought it was related to that, but now that Amelia is getting ready to lay, it has become VERY obvious there is something wrong with Cora. She has no comb or wattle to speak of. She is pale and stands away from the flock sometimes. She seems to eat well, but waits until she is alone or with her (very loving and protective) sister. Her feathers are dull in comparison. She has always been bottom of the pecking order, but her lack of maturing has us worried. You can tell which bird she is in the pictures.