I had some chickens and most of them weren't laying anymore so I gave all but 1 barred rock away (She was laying great, and wasn't as old). I got 14 new chickens that I put in with her and she was still laying an egg a day. Then after a few months she just stopped. She hasn't started laying again. What could cause this and do you think she will start laying again? It doesn't look like she is molting or anything like that.