The Book Thief
by Markus Zusak
At the beginning of the novel, Frau Holtzapfel is Rosa Hubermann's enemy. She spits on the Hubermanns' door every time she goes past it. The relationship is soothed when Frau Holtzapfel hears Liesel read from The Whistler while in the bomb shelter. After that, she trades coffee and flour to Rosa in exchange for Liesel reading to her in her home.