The issue seems to be BOUNDARIES....MIL has none. You must set the boundaries. As long as you enable her be letting her use you, the results will continue to be the same. Do not buy, give or "loan" her anything. It sends a "mixed message" and encourages her to continue her bad behavior. Speak in short, simple sentences. Do not make excuses to her. A polite no should suffice. When she asks why, whines, or tries the guilt thing, YOU have the choice to give in or stay strong. "I am no longer going to give you anything. Try the salvation army, etc."