The first thing Miss Maudie does is feed the children cake, this is always a good way to help children feel better about the world. For Miss Maudie it is alsow a way of helping them to feel that "nothing has changed."
Miss Maudie then trys to outline all the things that the people of Maycomb have done for Tom Robinson. She points out that the judge appointed Atticus to be his lawyer, obviously in the hopes that he could perhaps win the case. The least-experience lawyer in the court normally got the cases like Tom's but obviously the judge hoped to give him a chance by sending Atticus to be his defense attorney.
Maudie explains to the children that many people in the town have good intentions but they cannot all follow through on them like Atticus and so they ought to be more content to see that at least in him they have a powerful example of goodness and honesty.