As another day starts for me and draws to an end for you MJ, even those of us of sunny disposition start to feel a little glum. If I were you, I would leave it one more night - I would not candle, because you are in the lockdown phase, and there is a reason the broody stops turning at this stage...
that's true that's it's too late once she leaves. But it's not true the eggs are infertile - we know the welsummer was fertile, and we do not know about the bantams, yet. She would not have been coo-ing unless she detected sound or movement from the eggs under her.
She might yet have chicks. I...
"back" - this is about hatching artificially, not with a broody. I think it's a very bad idea; not a port in a storm but a shipwreck.
Keep faith with Mary until she leaves the nest. She knows what she is doing better than we do. If she gives up on the eggs, so should you.
fwiw, in my experience the very gentle coo-cooing from the hen is encouragement to chicks to hatch; it is often the very first thing I hear. So there's a usually a significant time between hearing that and seeing the chicks. Don't presume it's over till the fat lady sings, as they say. If you...
Mary will leave when she feels it right, with or without chicks. Let her be your guide. Don't give up until she does. They could be hatching or sleeping beneath her. Try to focus on your meeting today.
so today is the first normal day, and it is not even over there yet is it? Keep sitting on your hands MJ. You are crossing bridges before you've got to them. And fwiw, chicks here typically spend the whole or almost the whole of their first day after hatching sleeping under mum, and just...
it's exhausting for them all. It could stop start for 24 hours plus. Just sit on your hands. I know it's hard, but it's the best thing you can do, usually.