We have a small urban flock in our small urban yard--6 hens (4 aurakanas, 1 rhode isle red, 1 plymouth rock barred). Sine the addition of the two latest aurakanas, the whole pecking order has changed and the new leader seems to think she needs to crow each morning just before sunrise. She tries anyway. It's a rather strange sound accompanied with flapping wings. Did I mention SMALL urban yard? Annoying the neighbors is an understatement. I heard that when you have a flock of all girls one of them may want to be the "roo", but she is takings things a bit too far. Is she normal? Within chicken reason, I mean.
With no roo, it is not uncommon for the lead hen to start to crow and act like a rooster. Best of luck.