In case you haven't read the book, Anne Frank was an outspoken, talkative and optimistic person; Margot Frank was a very shy and quiet person.
They're both hiding in the annex so that the Nazis don't find them and send them to concentration camps. Â The relationship between them is that they are sisters. I'm not sure what they disagree on, I read the book long ago. But Margot was much more mature than Anne, so it was probably something about that.Â