i dont know a lot about leghorns but it seems that the ones thats combs flop over are hens and the roos (usually) stand up......dont know how true this is, its just what i have observed so thought id throw it out there
She's definitely a leghorn, but her legs are really yellow, which to me indicates that she's not laying. My leghorn girls' legs bleach out pretty quickly after they've started laying. And they have started laying between 16 and 20 weeks. So if she's already going to be a year old in May, she should already be laying...