The we shall expand the story! As long as it already is, I'm pretty confidant they could easily do so. Imo, I think it would fit quite nicely as a continuation for their saga, going from a sexually disinterested sister, to a curious one, to a lewd one, and dealing with the consequences of it one way or another. Maybe they decide to abort and she become infertile as a result, in her grief the player consoles her and assures her they still love her and will do so for the rest of their lives. Gameplay would take a lewd break to focus on cheering her up. Or, they decide to keep it, hiding it from their friends and family until they need to tell their mother so they can pull her out of school and go from there, fighting the disapproval but eventually gaining acceptance. There's a lot they could do with this if they chose to without ruining the story, and I would personally love to see it developed further, ideally with a pregnancy path, but to each their own.
If I understand you correctly, you would rather they story remain as it is, and I get it, some people read the book and are happy with just that. They don't need the author to come out with a sequel, they prefer the story as it was written.
TBH, I'm just desperate for some great vanilla pregnancy games, so many are either completely devoid of player input, full of corruption and abuse, or has tentacles/monsters (not bad in and of itself per se, but does not lend to a vanilla experience). This one was leaning that way with some of writing and the gameplay is overall very satisfying so if it could just take that extra step, I'd be happy.
