What Does Mr Dubose Mean To Be Brave

Mrs. Dubose is not as brave as Atticus says. While Jem and Scout are walking into town, Mrs. Dubose says, “Your father’s no better than the n****** and the trash he works for!” Mrs. Dubose says this to hurt the children's feelings. Later Atticus refers to Mrs. Dubose as brave, but I would consider this anything but brave. She is going out of her way to hurt the feelings of defenseless children.
This is not something a brave or courageous person would do. A brave and selfless individual is someone who sets an example for others. Putting down little children is petty and disappoint. Displaying this kind of behavior is not something that should be classified as brave.