Ok rereading I think if your very generous the "do you want to make a baby" can be waved away as her asking for a sibling.
We know its not that. But I feel thd author was trying to show that but sis picking up that she dosent wasnt a sibling but a child of her own
Crazy to think this is finally over. Of all the mangas i read over the years this was the one that got me through the tougheat of times from getting over exes to ex fiancée's
Thank you so much for being able to finish this it means so much to me