Well, I sure am glad we got that settled! LOL
She has NO black feathers on her chest. Her comb isn't red at all. and the other chick/young pullet in with her is Rusti the RIR.. and has this tiny little comb, so even if Coco's comb is normal for a young leghorn pullet... it looks HUGE compared to Rusti's.
Either way, I have decided to continue my search for an Americauna breeding pair.