8 month old RIR not mature or laying

[cbeery]

I have 3 RIR hens, 1 Barred PR hen and unfortunately 1 Ameraucana Rooster. They are all the same age, 8-9 months old. 2 of the RIR have been laying several months and the PR about one month. One RIR hasn't matured like the others. She has a very tiny comb and wattles, however she is the largest of the hens. She is not laying. The rooster is constantly harassing the other hens, but leaves this one alone. I was wondering if anyone knew what could be wrong with her. Are some hens just duds? At this age, I'm positive she is not a rooster.

 

[sumi]

I had a RIR X hen that surprised us by laying her first egg when she was just over 8 months old. It happens sometimes. My hen was a bit of a dope and she was too fat, I'll admit that!