I still don't think it is frostbite. Frostbite will turn them black. I've experienced frostbite on roosters with huge combs and wattles when it got to single digits and especially when it got significantly below zero F.It has possibly been to the single digits F for just a few hours in the early a.m. I think I'd rather it be a bit of frostbite than lingering illness! I was of the understanding that Ancona Chickens come with either the flop comb or a short comb, but I didn't get a choice when ordering and just crossed my fingers, but she came with the flop comb. I really like this spunky gal, I'm hoping she gets over this like she has overcome all her other woes.
I've never had frostbite on hens in the same conditions, even with large single combs like Anconas, Leghorns, Minorcas and Penedesencas.