What does Scout teach Atticus in ch 13?

Near the end of Chapter 13 of To Kill a
Mockingbird, Atticus Finch attempts to teach his daughter, Scout (Jean
Louise) that she must obey her Aunt Alexandra's dictates and adopt a much more ladylike
approach to life than she has exhibited previously; Jem, Atticus's son, is to behave
himself as a proper young man of quality lineage.  Aunt Alexandra, who is somewhat of a
snob, feels that Scout's behavior reflects negatively on the Finch family
name.

"...She
asked me to tell you that you must try to behave like the little lady and gentleman that
you are.  She wants to talk to you about the family and what it's meant to Maycomb
county through the years, so you'll have some idea of who you are, so you might be moved
to behave
accordingly..."

Have been
told, basically, that her entire way of conducting herself is no longer acceptable,
Scout attempts to comfort herself with an innocent distraction, but Atticus admonishes
her harshly for making noise.  Scout is driven to tears, because she sees her father's
uncharacteristically stern and unkind behavior as evidence of an impending great change
in him brought on by the inevitability of Tom Robinson's trial.  When Atticus realizes
that Scout is merely doing her best to mask her fear and upset, Atticus tells his
children that he doesn't "want {them{ to remember it.  Forget
it."

Atticus, who represents the best of morals and ethics
in nearly every way and is an exemplary father, friend, and citizen, finally recognizes
the truth of his sister's advice and promptings when Scout comes to him in tears. 
Alexandra had instructed Atticus to force his children, in essence, to conform to
societal standards and care more about what other people expect of them than their own
sense of appropriateness.  In doing so, Atticus betrayed himself; he allowed his sister
to influence him and went against his own morals.