why did scout begin to cry in front of atticus?

Aunt Alexandra tries to pressure Atticus into telling the children why they should behave and "live up to your name." Atticus makes an attempt, but when Scout begins to get upset with this strange side of her father she has never seen before, he returns to his original principles and finds himself incapable of passing on what Aunt Alexandra deems important. Scout is relieved when her father returns to the same old Atticus, and says she knew what he was trying to do, but that "it takes a woman to do that kind of work."