Clarisse asks that Montag why he doesn't have daughters like her. Clarisse is like a daughter in that she is inquisitive about the world, but somehow wiser than all the adults. On page 27, in my copy, Montag tells her she sounds old. She replies:
Sometimes I’m ancient. I’m afraid of children my own age. They kill each other. Did it always used to be this way?
Clarisse represents the wonder and creativity with which children look at the world. Growing up in this dystopia, Montag probably missed out on this perspective. She is the first to ask if Montag has ever read the books he burns. She is also the first to ask if firemen used to put out fires as opposed to starting them. She initially sparks his curiosity more than any other character.
I’m not sure I would simply characterize their relationship as a father/daughter dynamic. They both learn from each other and Clarisse represents an alternative or foil to Mildred which is to say that Clarisse is, in an innocent way, a romantic infatuation as well as a platonic one. I would say that Montag learns more from her than she from him. For lack of something more definitive, I would just say that they are friends. They are so different from each other that each seems exotic to the other; as if they are from two different countries. Maybe I would use exotic friendship. The implication of exotic means foreign, different and curious.