How long after 21 days to leave eggs under mama?

[CityGirlintheCountry]

My mama silkie was sitting on 7 eggs. Five went under her on one day, one the next and one the next. Four of the initial eggs hatched on Sunday (day 21). The one that should have hatched yesterday has a crack in it but no pip. It hasn't hatched. The one that should have hatched on SUnday has no pips or cracks. The one that should hatch today has no pip yet. Mama hen is happily sitting on four chicks, but I'm not sure she's paying attention anymore to the eggs. She hasn't pushed them out from under her or anything. She just doesn't feel as dedicated to them as before the first round hatched.
How long should I leave the unhatched eggs under her? One is now on day 23, one on day 22 and one on day 21.

thanks!

 

[suebee]

I've had a silkie egg hatch on day 25 so I'd wait a few more days.

 

[CityGirlintheCountry]

I just checked on mama and noticed the standard egg was seeping yellow. I took it to the compost heap and it kinda exploded. I'm going to go with that one was no good.

The two left are banty eggs. They are cool to the touch with no sign of pipping or anything. I nudged them out to look at them and Fifi very grumpily nudged them back under.

The cool to the touch part bothers me. It was down in the 20s last night. Fifi is still hunkered down over the 4 hatched chicks and the two remaining eggs. I guess I'll let her keep at it. Beats me.