Children's books are generally designed for children of a certain age group. For underage children or children with reading disorders, like dyslexia, there may be passages of the books that are difficult to understand. This can be due to words not known in the vocabulary of underage children, to words made of complex subparts (to pronounce, for example), or to the presence of anaphoras that have to be resolved by the children during the reading. In this paper, we present a study on diagnosing the difficulties appearing in French children's books. We are more particularly interested on the difficulties coming from pronouns that can disrupt the story comprehension for children with dyslexia and we focus on the subject pronouns " il " and " elle " (corresponding to the pronoun " it "). We automatically identify the pleonastic pronouns (e.g., in " it's raining ") and the pronominal anaphoras, as well as the referents of the pronominal anaphoras. We also detect difficult anaphoras that are more likely to lead to miscomprehension from the children: this is the first step to diagnose the textual difficulties of children's books. We evaluate our approach on several French children's books that were manually annotated by a speech therapist. Our first results show that we are able to detect half of the difficult anaphorical pronouns.