To be clear, I didn't ask the question to ascertain if the game is complying with my preferences or anything like that.
If the relation is the of "steps" or not, in this game, I really don't care either way as both would be equally good in this setting and with the writing as it is.
I asked because I was under the impression that the donating babies to the temple and picking sons and daughters from it was the norm. Maybe it is, or maybe it's just an option. Either way I'm unsure and wanted that clarified, that's all.
I believe there's a line of dialog making a reference to the Queen herself, one that mentioned that the previous Queen had adopted her and the same happened with the one before that.
The main purpose behind the establishment of the Temple of Zeta is for population growth, basically a human factory. There is no point of donating babies to the temple, instead it is for the citizen to adopt babies and/or children.
Incest
If the player set blood relation, then
Shani and
Ain are
Zaton and
Zahra biological daughters through the natural procreation process. However, if the player uses the default relation, then
Shani and
Ain were adopted from the Temple of Zeta, they become the stepchildren of
Zaton and
Zahra. In this case, the player mental gymnastic can become handy. The player can create a backstory where
Shani and/or
Ain were actually fathered by
Zaton, where he fucked one or 2 priestess. Practically, in this scenario it is incest. The default backstory is that the player is never told who was the father and mother of
Shani or
Ain, and it really doesn't matter.
Anyway, that is just my understanding of the lore. I could be wrong because I am not the storyteller.