No, given the informations, i believe their mother is Nymiera, since Anathea was already dead, on Zone Zero Isiah's files the apparel of "Anathea" checks with Nymiera's. I also believe the Archetype may have been divided and implanted in them
I already bred more of 50 gibles, and none of them is shiny, but when i was breeding magikarps in episode 16, at least 3 of 20 was shiny.The shiny rate decreased, some pokémon have bigger shiny rates, or it is just my bad luck attacking again?