BCM making weird nosie

I have a BCM that is making a odd noise that started today. She has been doing it all day, at least when I go out there she is. She is acting normal and not mouth breathing either. To me it sounds like a cow. If you close your mouth and make a cow sound that is what she sounds like. Her color is good her eyes look good and she does not seem to be in any pain or stress. She is just walking around making this continual noise. Any ideas? I have only had hens for about 6 months. Oh, they just came out of molting and about 6 of the 9 started laying again. Dont know if that has anything to do with it. She is of laying age, she was laying before molting.