Are you saying you have to use one of these two books, or can you choose another? Unfortunately I don't know either of them beyond the title, but it may help to start by thinking about what themes and relationships come to mind and try to devise you question from there. How does the author illustrate a particular theme, for instance, or a comparison of relationships.
Would you be 'allowed', do you think, to make a comparison/contrast between two books' treatment of a particular topic?