I assume that you are talking about what happens in the first chapter of the book where Lily and her family are talking and doing their thing where they share feelings. She talks about the boy from the other community and how he annoyed her.
If that's what you're talking about, what the dad does is to get her to look at things from the boy's point of view. He points out to her that they boy probably felt out of place and stupid because he did not really know the rules of this place. So he gets Lily to put herself in the boy's place and to feel sorry for the boy instead of being angry at him.