Pullets generally start laying around 6 months old and I've heard they can start laying as early as 3 months old. I'm not sure if this is true, I've never had them laying that early so I don't know. The combs look quite pale still so I would also guess under 6 months.
Wow, they actually are Ameraucanas! I clicked on this thread expecting 4 replies saying "umm call them what you want but those are Easter Eggers"
McMurray sells to a ton of farms around here and many of them seem to take the hatchery's word for it (why shouldn't they) but they are actually selling Easter Eggers. I have two of them, sold to me as Ameraucanas, but at an Easter Egger price so I am fine with that.