Well...i know i'm possibly reviving an older argument but how could Meia "got" Hibiki's genes?
Possibilities:
1.) Hibiki donored it.
2.)Hibiki cheated(we can't blame him...he's a human being too)
3.)Hibiki got two wifes(ore even more...)
4.)Hibiki divorced and remaried.
Perhaps the first one the most possible than the second and so on.
Looking on the pictures I'm somewhat glad that it didn't got animated(well..instead of Dragonauts everything is fine
). Somehow I sense it weak...perhaps it's my only guess after seeing a couple of pictures.