Demon/Angel Asian Families?

[Archangel Beth]

Don't forget "twins." Or "triplets." If you have a birth and a child, then sneaking another one in isn't impossible -- and might even be done in a suitable hospital, if the mother is sufficiently distracted/unconscious! (In a modern setting, this might require an ultrasound tech being in on the masquerade, and the birthing to be considered "high risk" in some fashion, such that it would, say, require a c-section. Could be pretty tricky, but if you have the right crew in place, could also be a slick way of putting a baby vessel into place.)