According to The Hollywood Reporter, Hilary Duff has joined the cast of the comedy Stay Cool.

IN TOUCH WEEKLY reveals Hollywood’s Most Powerful Sisters. They started earning money when they were 9 months old, and Mary-Kate and Ashley Olsen, now 22, have never stopped. As co-presidents of Dualstar Entertainment Group, the twins have an estimated combined net worth of $100 million and they oversee an empire that sells $1 billion per year in clothing, books, furniture, videos, dolls and a slew of other merchandise. “We couldn’t do this if we weren’t best friends,” says Ashley. “If we weren’t really close, we’d rip each other’s heads off.” “We do everything for our company,” says Ashley. “In that sense, we feel powerful.” “It wasn’t about acting. It was about making kids smile,” says Mary-Kate of the twins’ early roles. The Olsens were self-made millionaires by the age of 10. “We have the same ultimate business goals,” says Mary-Kate of sister Ashley.

The ENQUIRER reveals Hilary Duff's big time binge drinking.

Hilary Duff's “good girl,” title sits fine with her, OK reports.