Nephew manipulates and drains 75-year-old mother's money

Dear Eric: My sister-in-law is 75, divorced and has a useless 40-something son. He has never held a steady job. When he does get a job, he finds some excuse to quit or else says he got injured. He then comes home and eats and drinks to his heart’s content. Then he will convince her he has an opportunity, so she gives him some money, and he disappears for a while until the money runs out.

There is no evidence of physical abuse yet but plenty of yelling and telling her she’s a bad mom to manipulate her into giving him money. She has enough resources to support herself but not enough to support two people.