Four eggs hatched but two Cochins eggs remain, what to do? Pics inc.

[denco5]

I have had four of the six eggs hatch in the last 20 hours I still have two cochin eggs that she is sitting on, is there still a chance they will hatch? These four chicks hatched in just 20 days so to me that is early so maybe the cochins are on schedule. Any advice would be great.

Thanks