Ok this morning I heard one of the step sisters crowing like a rooster. I went out there and she just kept crowing it was cute but annoying since we have neighbors. Eventually she stopped when I gave them some apples. What's up with that?
If you are certain she's a hen, then this really isn't that uncommon. Basically, the girls are deciding that the abscence of a rooster means someone has to take charge. Your girl says, "Listen to me, you follow my orders now," and in return crows like a male would, trying to stimulate her status. If this continues, you may even notice her trying to mate the other hens, sometimes they will even grow spurs and stop egg-production.
I have had them since august I think and they came from a ranch with roosters so they were use to roosters and hatching eggs. After I went out there and fed her apples she stopped. A friend of ours in 4H said she is probably the Alpha female and she is because she is always the one to tell me someone laid an egg.