Yep! I check her bottom everyday Her comb and wattles are still pretty small - I'm no sure how big BSL combs are supposed to get?Pay attention to her xomb & waddles. They will get plump and more red. I would randomly, 1 time a day, sit mine in the nest box. They would bolt or check it out. Keep doing that until they eventually check it out on thier own. I would also do pelvic bone spread check at bed time, make not of her spread number. Then when you get a new egg, do another pelvic check..so you know who laid the egg.
Make sense?
As for the rest - Just looking at their physiques, the other ones are no where near lay