But i think I already know the answer,
so in a nut shell, her father wanted to make the beast with 2 backs with her? =/
Yes. That is, he wanted to marry her.
Here's one version of the story:
Great find violet
So it is a real story. I thought they just made it up for the game.
Oh, it's definitely real. I remember reading that one when I was a kid and being like WTH? Lol. Not to mention, there are actually several similar stories about a man who wants to marry his daughter (so many that there's actually a classification for it in folklore), like the Grimm's Allerleirauh and a few others. It's weirdly common in folklore and fairy tales, for such an odd theme.