I'm obsessed with the Leghorn body-type. Sadly, I only have one purebred. Here is her son, who is a Leghorn cross. Also, you know you have a BCM cockerel, right?
Yeah, she is an Austra White. With that white skin, she can't be from the others. GLWs, BRs, and WLs all have yellow skin. I would just call the brown spot leakage.