Christa Wolf wrote her fictional autobiography titled Patterns of Childhood in a way that she actually does not use standard, more typical first-person narration. Instead, Wolf recreates herself as a fictional character named Nelly Jordon; as a result, Wolf relays all of her childhood memories in the third person by referring to Nelly Jordon as if Wolf's own personal childhood story was really Nelly's story.
Hence, the relationship between the narrator and Nelly is that they are actually the same person. As Wolf narrates the story of Nelly, she actually narrates her own personal story. Wolf's reason for writing her own autobiography in such a way was to give herself a chance to face the fact that, as a child growing up in what is now East Germany, she became involved in the Nazi regime. As Wolf has difficulty reconciling her adult self with her child self, writing the book using a third-person narrator to tell the story of Nelly also gives her a chance to cope with all of the trauma associated with growing up under the Nazi regime and find her true self.
Lenka is Christa Wolf's, the narrator's, real daughter. One of the reasons why Wolf created Nelly's character is because, as the editor of Literary Essentials: World Fiction, Frank Northern, phrases it, she "finds it difficult to explain to her daughter, Lenka, how Nelly could so eagerly submit to her [German] teacher's [Herr Warsinksi] demands for unflinching obedience and faithfulness to the Fuhrer" (eNotes, "Summary"). Of course not; how can anyone easily explain the traumatic experience of being brainwashed through propaganda and the effects of brainwashing? Hence, it can be said that Wolf created Nelly as a means to explain to Wolf's real daughter Lenka what Wolf experienced as a child, while also distancing herself from her experiences.