To kill a mocking bird, i need a quote from chapter 10 and why the quote is important

"After my bout with Cecil Jacobs when I committed myself to a policy of cowardice, word got around that Scout Finch wouldn't fight any more, her daddy wouldn't let her. This was not entirely correct: I wouldn't fight publicly for Atticus, but the family was private ground. I would fight anyone from a third cousin upwards tooth and nail. Francis Hancock, for example, knew that"

Why is important:Atticus is the same in both public and private, but not Scout she's willing to toe the line and play it cool with outsiders, but she still fights with her own family. Is Atticus's opinion the only reason, or is there some other difference?