Well its obvious they're not pure silkie chicks.
The "black cochin" isn't a pure cochin. Its a mix breed. He is also not pure for black so everything's up in the air for him. No telling what genes he can be passing to offspring.
I think you have something wrong with the suspected parents.
They sure aren't from a partridge silkie Xs buff silkie.
Also don't believe they're from a silkie Xs black cochin. That cross would produce black or mostly black chicks.
Neither even look to be silkie at all.
I'm confused how they...