Day 28 Only one egg of 12 has hatched

[NMChickChick]

Momma is still diligently sitting on the unhatched eggs. She has been up and taught the one chick (hatched day 21) to eat and drink but always returns to the Unhatched eggs. Should I remove them at this point?

 

[Ol Grey Mare]

Were all eggs set at the same time? Candle and remove to incubate if good or toss if bad.

 

[NMChickChick]

Were all eggs set at the same time? Candle and remove to incubate if good or toss if bad.

They were all set at the same time and marked so I know there is no new ones. Is it ok to pick up the eggs to candle? I thought I should leave them since we are past day 18