How did Mayella Ewell ruin Tom Robinson's life and harm his family in To Kill a Mockingbird?

When Scout and Jem go to church with Calpurnia in Chapter 12, they learn that the Robinsons are struggling financially. 

Tom Robinson is a family man.  He has a wife and children.  When he is accused of rape by Mayella Ewell, obviously this ruins his life because he loses his liberty and is falsely accused of a terrible crime.  His life is also in danger because there are people in town who want to skip the trial in favor of lynching because he is black and Mayella is white.

When the children go to church with Calpurnia, they get another perspective on how Tom’s arrest has affected his family, especially his wife.  Reverend Sikes asks for the congregation to take up a collection to help Tom’s wife, Helen. 

“You all know of Brother Tom Robinson’s trouble.  He has been a faithful member of First Purchase since he was a boy. The collection taken up today and for the next three Sundays will go to Helen—his wife, to help her out at home.” (Ch. 12) 

Mr. Sykes says that Helen can’t leave her children to go work.  When Scout asks him why Helen doesn’t just take the children with her, as is customary for field workers, he tells her that there is actually more to the story. 

Reverend Sykes hesitated. “To tell you the truth, Miss Jean Louise, Helen’s finding it hard to get work these days… when it’s picking time, I think Mr. Link Deas’ll take her.” (Ch. 12) 

The ostracizing of Tom Robinson’s family is not unexpected, given how Atticus is being treated for just defending Tom Robinson. Calpurnia tells Scout that folks “aren’t anxious to—to have anything to do with any of his family” because Tom Robinson was accused of rape.