For Kylie Jenner, selling a chunk of her four-year-old make-up company at a rough valuation of $1.2 billion   cements her status as a mogul at the age of just 22. Photograph:   David Dee Delgado/Getty Images

Coty is buying a controlling stake in Kylie Jenner’s cosmetics company for $600 million (€542 million) in a bet that the youngest Kardashian sister’s (...)