My conspiracy theory to reject incest is that the little girl was born from her mum and sperm donor maybe (?)
The title "jinx lover" means the 'first guy' to have physical contact with the jinx..that title doesn't mean you have to make love..(i hope this is true)
So every president generation would just need to touch the jinx to get premonition
So incest theory becomea void~
I don't remember any scene that proves the little girl was the president's daughter..correct me if I'm wrong~
╮( ̄▽ ̄)╭
I agree. With sugwang (the black-haired mc) she only had to have skin contact, so it's not like there was no way other than incest for the men in that family to keep getting good luck from the women.
We can rest assured now, that she's not the president's daughter: they reproduce asexually (though that's even weirder...)

the littler girl is the president daughter and her son will marry her????! wtf