The relationship between Ilsa Hermann and Liesel Meminger is one fraught with tension. Liesel does seem to be a bit angry with Mrs. Hermann for not continuing to have her laundry done by Rosa. Liesel thinks that the mayor and his wife must still be able to afford Rosa's services even though Ilsa says that they cannot. Liesel does not feel guilty in any way for stealing a book from Ilsa's library and figures that the lady will not even notice that one book is missing from among so many. Once Ilsa notices that Liesel is stealing books from her, she does not scold the girl and figures that she must be in some way starved if she resorts to breaking into her library. Ilsa feels that she can provide Liesel with what she needs, so she allows her to come into the library. But the two remain relatively guarded and thus the relationship is tense. Liesel never really trusts Ilsa, and Ilsa is unsure of Liesel's motives. Their relationship is symbolic of the ultimate tension of the time in which they live--the circumstances of the war do not allow them to have a bond that they otherwise might have.
Ilsa Hermann is the mayor's wife, and Liesel gets to know her by dropping off and picking up laundry from her house. Liesel does not think that Frau Hermann, who seems distant, has seen her steal a book from the mayor's library. When Liesel next shows up to collect the washing, however, Ilsa Hermann hands her an entire stack of books. Ilsa takes Liesel to the library and allows her to browse through the books, delighting Liesel. Eventually, the mayor's wife has to cancel the laundry service provided by Liesel's foster mother, but she says that Liesel can continue to read in her library. Liesel responds with anger, telling Ilsa that she should have long ago gotten over the death of her son in the last war.
In response, Ilsa writes a letter to Liesel telling her that she knows she is stealing books from the library and asking her only to come in through the front door. Ilsa eventually befriends Liesel and gives her a book in which to record her thoughts and stories, encouraging her to be a writer. Later, she takes Liesel in after her house has been destroyed. By befriending Liesel, Ilsa is distracted from the grief with which she has enveloped herself; Ilsa is revived a bit by caring for Liesel rather than wallowing in her grief.