Does that make the dialogue like "Daughter, are you listening?" or "Good morning, daughter?" because that would break the immersion as nobody talks like that to their daughter. Perhaps, giving the daughter a desired first name, but naming the father as "dad" would be better.
Actually, what happens is you give the two characters names.
Then it asks, "What are you to her? her...". This will be used extensively when the girl talks to the guy. If you're going for incest, "Daddy" would be a good choice.
Then it asks, "What is she to you? Your...". This one is mostly used descriptively by the narrator, but occasionally used by the guy, speaking to the girl. [He mostly uses her name, or 'sweetie'.] I used 'baby girl'. It works, but could be better... 'Cumbucket', might be a little weird!