So, I missed the start, so this is a bit skewed/truncated
Liked: I think OUAT is at its best when it is unapologetically structuralist, with big, mythic themes that are then explored through the characters and their relationships to each other both as specific characters, and as avatars of certain archetypes. There was something of this in this episode. By making Gideon and Emma total, almost mythical antagonists, the kinship tree clicks into place, such that Snowing and Rumbelle also become mirror images of each other — as I think the show hints at from the beginning, whereby if Snowing is the couple that, by its very nature, always finds each other, Rumbelle is the couple that always loses each other (which also explains somewhat why they’re such a stable pair despite the clear dysfunctions). It also highlights the potential parallels between Emma and Gideon, which also makes them sort of mirror images of one another.
I hadn’t thought about it before, but I think you’ve really got this one nailed with the mirror image families. Perhaps Henry as the product of dark and light can help? …sorry I just laughed when I read that last bit.