Have you actually looked under her? Have any of the eggs pipped? Can you hear any noise from them? I have read that some members have had successful hatches up to 25 days. Both mine have started to hatch day 21 with most being actually born day 22. I'm not sure about what happens with the broody hormones if she donsn't get chicks! Do you have somewhere you coudl buy a couple of day old chicks from to tuck under her? My first hen didnt' let me get near her and I didn't really see many of the chicks until they were a couple of days old and they came out from under her so is there definitely none there?
I have read that it takes a week for every thing to start work in the way we like for it to work and I only ask about the rooster because you side 1 or the 4 was yellow in side I have no clue as to what that means.