I have had several hens that crow. What an awful sound - half yell, half poorly formed cockadoodledoo. They have never done it as nearly as frequently as a rooster - usually a few times in the morning and that's it. it's never been enough to annoy my neighbors. Mine have never stopped laying, though. The crowing habit seems to come and go - they do it for a week to a month, then stop, then it might come back. I've only had one crowing hen at a time, it is always the top hen, and it seems to make sense that they are taking on part of the role of the rooster because I don't have one I have never heard that it was related to a deficiency. I have heard of 'transgendered' hens that crow, stop laying, and that develop male characteristics (permanently, I think) - big comb and tail but I think this is much more rare than your fairly common crowing hen.
I think odds are that your hen will crow occasionally (nothing like a rooster), may stop crowing entirely, and resume laying....i hope that's what happens!
