Although, the game has everything for wincest (juicy MILF and her daughter) as some people are wishing for. But the author has scripted and modelled the game in non-incestual way. So It definitely will take time to rewrite the scripts in incestual way. But it might not be as good as a regular incest mod. As the plot has many instances where Lumi's mother behaves formally with MC. So how it's gonna be possible if the to-be-mother character doesn't talk to MC like a mother.
Another alternate plot would probably be keeping the Mum dead, and make MILF and girl, Aunt and cousin. That would probably require less work and still scratch the wincest itch.