Friends daughter Belinda is a harlot, an alci, and crazy, what to do?

My friends daughter is married and has 2 kids. She needs a whole bottle of wine a day, doesn't want to cook. She does anything for money,. She was a Playboy Bunny and an Escort before marriage, husband doesn't know. We were hoping she'd straighten out and be a nice person. No such luck. She's even slept with her brother in law.She's also a cunning liar and manipulator. My friend, her poor Mother has been accused of horrible things, which are untrue.She's become best buds with her father's rich black girlfriend, by selling her own mother out, to gain sympathy. we also think it's beacuse of the money Blackie has. What can we possibly do to stop her craziness? Can her mother file a law suit for slander? Or what