My problem was that the story itself makes it so that even by setting the relations differently, the story itself makes it so that anything other than incest doesn't make any sense, and it could all be easily be remedied by changing relatively little in the wording of some lines of some characters in specific scenes, so long as a proper relation is established for Klara to be something ambiguous instead of certain.
Then people that want her as mother will be happy, but people that want her as aunt, step-mother, adoptive mother, legal guardian or whatever else will be happy too. All that's needed is to not confirm beyond any doubt the pregnancy and the relation with Jovian.
Everything lined up really well with the relation for her set as aunt (or guardian) until the Hera scene that mentions Klara's pregnant with the MC with Jovian being the father.
Sky is much less of an issue, as she mainly (at least so far in the story) only needs to be somewhat consistent with Klara's relationship to the MC and needs to be in a "frowned upon" position as the MC's lover (cousin, step-sister, and adoptive sister could work just as well as being the actual sister, for example).
I get that there are many times that the whole "have your cake and eat it too" is impossible to achieve, but it is not the case in this game. This game presents a perfectly possible way to implement a way to please both people that are into incest as well as those who are not by making some very small changes.
That's on account that before that Hera scene, the story up to that moment was very well written to the point that several different types of relation settings worked. But after that scene, only one makes sense.
