Should we be concerned??

[Hoytantarian]

Our silkie hen has been sitting on her eggs for just over 21 days. Two have hatched and are fine, but 5 haven't. It's been 5 days since the first chicken hatched; the second came 2 days later, and their hasn't been any others since. One of the eggs was trampled on by the other chickens, so we know that one won't make it; we moved the Mama into her own private space after that. Is there something we're doing wrong and/or should we keep on waiting?
Thanks!

 

[CMV]

Have you tried candling them to see what they've got inside?