Nineteen-year-old Shu Pei has become one of fashion’s preferred models, though that wasn’t always the case. Two seasons ago, New York casting directors failed to connect with her. But it was a completely different story in Paris. John Galliano cast Pei not only for Christian Dior, but his namesake label, too. Karl Lagerfeld then requested her to walk in his spring Chanel couture show this past January. When she returned to New York last week, confirmations from Ralph Lauren to Vera Wang were coming in left and right. Someone has made it to the big leagues.