Gypsy face, which is what the hen pictured exhibits, can occur in any breed but usually never shows up with barring. Gypsy face occurs when dermal melanin and other melanizers interact, but it is normally selected against.
Barring+dermal melanin is very rare. However, a hen gets the dermal melanin gene from her father, along with the absence of a barring gene. That, with the extended black gene of the barred Rocks may give you gypsy face, and it will definitely give you dark legs.
This is my Starling, a hen with a wheaten Ameraucana father and a Dominique mother.
So given the information that she is black with black legs and a dark face only narrows the father down to not splash and not dominant white with dark legs.
Barring+dermal melanin is very rare. However, a hen gets the dermal melanin gene from her father, along with the absence of a barring gene. That, with the extended black gene of the barred Rocks may give you gypsy face, and it will definitely give you dark legs.
This is my Starling, a hen with a wheaten Ameraucana father and a Dominique mother.
So given the information that she is black with black legs and a dark face only narrows the father down to not splash and not dominant white with dark legs.