Exactly that was done for Love Season: Farmer's Dreams (though a bit overkill imo, the whole village is related after the patch and not just Nina/Nova turned into cousin/sister)
I don't know Love Season, but again, a patch for Troubled Legacy makes no sense.
The story as such would have to be completely rewritten.
If you do that, you'll have a different game, but not the story as black wrote it.
And before you steal the work of other people who have invested a lot of time and money in it, you should consider creating your own game with everything that goes with it.