In chapter 16 how is Atticus's relationship with aunt Alexandra changing?

I don't think Atticus's relationship with his sister changes dramatically. Atticus applies the same gentle protests to her that he always has. Scout cries that night and Jem consoles her. Atticus says that Mr. Underwood despises black people, but was still willing to defend Atticus. Aunt Alexandra urges Atticus not to speak like that in front of Calpurnia, but Atticus protests as usual, claiming fairness and honesty are important.