The titular Mockingbird represents innocence. Atticus tells his children that they can shoot all the bluejays they want, they must remember that in his words "it's a sin to kill a mockingbird". When Scout asks Miss Maudie what that means, she says that Mockingbirds "don't harm any living creature" and "sing their hearts for us". Tom Robinson is the Mockingbird of the book - he couldn't have committed the crime but the town and the justice system of the time conspire to convict him anyway.
In To Kill a Mockingbird, the Ewell family is full of small children being raised by the eldest sister, Mayella Ewell, and nominally supported by the abusive father, Bob Ewell. It's said in the book that Mayella can't remember her mother. This implies that Mayella must have been very young when her mother died. Well then, since she clearly doesn't have a stepmother in her life, where did all these small children come from... oh. OH.
It's no accident, Tom Robinson actually states that Mayella told him "what her Pa do to her don't count" while trying to seduce him.
He said she told him this while asking him to kiss her. Kids reading may think she was talking about innocent "good night" kisses or the like, but re-reading the novel years later would make them realise that Bob Ewell isn't the kind of father who gives good-night kisses and that, at nineteen (and a half), Mayella Ewell would be too old for goodnight kisses anyway. This may have been done intentionally by Lee to shield children from the implications of Parental Incest.
There's also the description of Mayella as "heavyset". Granted, that could just be her body type, period, but it could also be the result of pregnancies.
After telling this to my sister, she came up with two alternate theories: 1. Mrs. Ewell died horribly, and Mayella tried to forget the trauma or 2. Bob's been sleeping around.
If Bob were sleeping around he would leave the children with their respective mothers. He is not the type of person who would bring the kids home with him. Also, why don't the mothers ever visit the children?
The mothers could have dumped the kids on him and left.
There's also the fact that when Tom says Mayella told him "what her Daddy do to her don't count" in court, yet it is not followed up, not even by Atticus. Unfortunately it is Truth in Television that at the time children who accused their parents of any type of abuse were often seen as lying to some end unless there was other evidence.
The whole thing is Truth in Television according to Collin Willcox Paxton, who played Mayella. She actually came from that area and has stated it was taken for granted that by the time girls were ten or twelve, they would have been raped/molested, usually by a family member.
Interesting note, actually, if you take into account that it isn't uncommon, even unto so-called modern times, where if a girl had a baby young and the father couldn't be found, said child would be played off as a younger sibling and often adopted or told as such, along with the fact that Mayella's mother is dead and her father doesn't say those are her siblings (actually, I don't recall him mentioning them), along with her apparently being the oldest of eight children, then it would make sense that some, particularly the youngest, of the Ewell children are hers.
An even MORE horrifying prospect: When he attacked the Finch children, what do you want to bet that there was a very real possibility Ewell would have raped Scout before killing her?
Probably not, however, he is a giant POS that such a thing wouldn't be past him but, odds are, he probably hadn't thought of it.
And still more horrifying—The final line of the previous chapter has Jem offering to walk Scout to and from the school. If he hadn't done so, she would have been alone when she was attacked, and would almost certainly have been killed.
In Go Set a Watchman, we learn Jem inherited his mother's weak heart, which killed him before he turned thirty. Likely this defect would have kept him out of the war.
Atticus also probably fought in World War I. No wonder he never spoke about his skill with a rifle.
He wasn't a veteran but an expert hunter. He stopped because he was so good he felt it wasn't fair to the animals.
One has to wonder how he would have got out of World War I. He's somewhere near fifty in the book, meaning he would have been in his thirties during the war, and the draft age went up to forty-five. It's possible he just got lucky and his number never came up, or his bad left eye kept him out, but it's a bit of a mystery.
One of the gifts Boo Radley gives Jem and Scout is what appears to be a war medal. Given his age and that the story takes place in the early 1930s the only war it could have been would be World War I. If Boo is a War Veteran his odd behavior might be explained by Shell Shock or Post-Traumatic Stress Disorder.
That was a spelling medal. In the book, Miss Maudie tells Boo's whole story. He was a completely normal child, an excellent student and could have gone to college. As a teenager he and some friends committed a semi-delinquent prank. Boo's father (a highly religious man) said he would discipline him rather than have him serve 30 days in jail. He confined his son to the basement. Boo was never allowed to leave the house again. That's why he acts the way he does.
Boo's father could have abused him to the point that he has Post-Traumatic Stress Disorder.
That is implied to have been part of the reason, the other because he wants to.
At one point in the story, Jem and Scout come across a rabid dog. They tell Calpurnia about what they saw, who recognizes the dog as rabid right away and shuts the kids away and calls for help. The thing is? The kids had no idea the dog was rabid. If they had decided to approach the dog themselves instead of talking to Calpurnia, they would have been bitten and infected.
Tom Robinson had one working arm and assurances from Atticus that he'd likely have his conviction overturned on appeal. He probably wasn't trying to climb over the prison walls when the guards killed him.
Tom's wife couldn't find a job during his trial and the church had to raise money for her to feed her children. She most likely also wasn't getting a job after he was convicted, leaving her children and herself penniless.
Tom's boss hired her as a cook after he was shot.
Likewise, Mayella now has to feed seven children and herself with no job, no friends, and no church to help. Her dad was a deadbeat, but at least he hunted and had some government money.
After Bob's death, she's probably getting the welfare money now.