This is certainly an interesting question because readers often do not think of positive qualities when it comes to the Ewell family from To Kill a Mockingbird. One might feel sympathy for Mayella and the horrible conditions she endures on a daily basis, but that is not the same as perceiving a character as courageous. Nonetheless, for Bob and Mayella, there are several instances where they might seem to exhibit courage.
Bob Ewell--He does not seem the least bit intimidated by Atticus who is certainly one of the most (if not the most) respected townspeople. He gives smarmy answers to Atticus's probing questions and enjoys the laughter of the crowd even though he is really in a serious situation. Most would interpret this as blind stupidity because Bob is "tricked" by Atticus into implicating himself in Mayella's injuries. However, if looked at as a whole, Bob knows that he and his family are looked down upon by the town, and yet he doesn't back down and even continues to "thumb his nose" at the judge and townspeople after the trial's end. Personally, I don't think that there isanything courageous about Bob Ewell, but you could stress that he is not easily intimidated, and to some that might come across as courage.
Mayella--Bob's pathetic oldest daughter is a different story. While one must grimace at her intention to use Tom Robinson and her insistence on lying to protect her debauched and abusive father, Mayella tries to defend herself in front of a judgmental audience. She is courageous in the sense that she tries to maintain self-dignity while on the stand. When Atticus calls her "M'am," she bristles at it because she thinks he is mocking her, and she stands up for herself in that instance. One may remember that while Mayella has falsely accused Tom Robinson, she is also a victim in the case. Harper Lee implies that Bob has abused Mayella in the past, and she must sit on the witness stand with her father staring at her and with Atticus, a skilled rhetorician, questioning her. While I do possess some sympathy for Mayella's plight, I would still argue that true courage on her part would be to tell the truth on the stand and face the consequences of her actions.
One of the authentic aspects of Harper Lee's novel "To Kill a Mockingbird" is the portrayal of the small Southern town and its types of residents. Within the poor community, for example, there are those like the Cunninghams, and then there are those like the Ewells. The Ewells are at the nadir of the socio-economic stratum; they are those that are often referred to as "white trash," whereas the Cunninghams are simply poor. The Cunninghams are the type of family that still retains some human dignity; they repay a debt by giving a person something from their garden, or working for the person they owe. When Walter is asked why he does not have a lunch, he says nothing. When Mr. Cunningham is addressed politely by Scout, he shows respect for her and her father and is ashamed that he is part of the mob before the jailhouse, and he directs the others to join him in departing.
However, no Ewell would do such a thing. The Ewells possess no redeeming qualities. Their behavior in the courtroom is not courage; it is a type of perverse bravado meant to justify to themselves their behavior and conceal from their audience what they really are. Steinbeck wrote, "The less a person has, the more he feels the need to boast," and this is true with the Ewells who have no redeeming qualities. For instance, Mayella repays Tom Robinson's kindness with open contempt; if she had any "courage," she would have spoken differently in the courtroom. Mr. Ewell shows nothing but depravity in his behavior.
The distinction between these two types of families is explained in Chapter 3 Scout talks with her father about the Cunninghams and the Ewells. Atticus explains the difference:
If he held his mouth right,Mr. Cunningham could get a WPA job, but his land would go to ruin if he left it, and he was willing to go hungry to keep his land and vote as he pleased. Mr. Cunningham came from a set breed of men.
But Atticus tells Scout,
...the Ewells had been the disgrace of Maycomb for three generations. None of them had done an honest day's work in his recolllection....They were people, but they lived like animals. 'They can go to school any time they want to, when they show the faintest symtom of wanting an education...[they] were members of an exclusive society made up of Ewells....when a man spends his relief checks on green whiskey his children have a way of crying from hunger pains...but he'll never change his ways.