Benny looks like a cobalt (possibly violet also) greywing opaline recessive pied to me

Assuming neither is split for anything, in addition to what Alexis mentioned above:
All of the chicks will be split for greywing (and all will be split for recessive pied).
The male chicks will be split for opaline and cinnamon.
The female chicks will be opaline.
If Benny is carrying violet also, some of the chicks will be violet.

Do you know anything about Nigellas parents or siblings? Do you have any pics of her as a chick before her first molt by chance?