I can only assume that you have come only recently to the game, thus the wrong information.The Patreon version is the canon as it is the only official version of the VN. So, the story is they aren't married and Marc isn't her biological child.
I am sorry you seem to be heating up about it, but the incest is the canon the way we both seem to define, i.e. the story as originally foreseen by Zorlun - what you can say, as Viressa pointed out, it that my version is not canon because is not the one diffused by Zorlun, but in that sense, there is effectively no canon version anymore since already some versions ago.
Zorlun had to take out the incest due to Patreon intervention threatening to ban him.
It is abundantly "documented" in the posts by Zorlun himself on this thread, just search for it.
I am not making a new story by putting back the incest, I am only keeping in an element that Zorlun himself had originally foreseen and was present in the game at the start and for some time.
It is one of my committments to Zorlun, I am doing the modifications necessary to have the incest and keep coherence with it, and I can make comments and suggestions for scenes like everybody else in the thread, but I am not creating a new story, if I spent the time to do that, I could as well create my own game.