Mayella Violet Ewell is the daughter of Bob Ewell in the 1960 novel To Kill A Mockingbird and 1962 film of the same name. Despite her not being the story's main antagonist, she is regarded as one of them due to falsely claiming she was raped by Tom Robinson when instead she had likely been abused by her father.
Mayella is the eldest daughter of Bob Ewell, and thus ends up having to take care of her siblings because her father is a strong alcoholic. She is physically abused by her father and becomes confused while testifying at the trial because Atticus asks her if she has any friends; she does not know what a "friend" really is. She wants a much better life, with nothing exciting to do. In court, she felt pressured so she kinda lied to the jury.
Mayella is the oldest child of Bob Ewell and an unnamed mother. The town speculates she's the one who keeps the flowers growing around the shack the Ewells live in. Later on in the story, involving the trial, Tom Robinson testified he had helped her with small chores at her request. The last time he did, she reached up to kiss Tom without his consent. Unfortunately, her father witnessed this through the window. Bob called In the sheriff and Tom was accused of raping and beating Mayella. The sheriff testified at Tom's trial that when he arrived at the Ewell's shack, Mayella showed signs of having been beaten. Despite all of the signs showing that the father, Bob Ewell, beaten Mayella, Tom Robinson is still found guilty. Mayella had lied to hide the fact that she kissed Tom. We also see that she despises being called upon respectably (When Atticus addresses her as 'Miss' or 'Ma'am') because it's not what she is used to and thinks she's being made a mockery of. After the trial, the citizens of Maycomb think less of Bob and Mayella, as Atticus suggests that Bob rapes Mayella along with beating her.