The 28-year-old supermodel Lara Stone has made a name for herself as a size 4 in a sea of size 2s and 0s. Discovered as a teenager in the Paris metro while on a family vacation, Ms. Stone slogged her way through seasons of casting calls before finally signing to IMG Models in 2006. That same year she walked in Givenchy's fall runway show. Since then, she has managed to gain momentum in a field where careers can last just a few seasons. Already on her third round of advertisements for Calvin Klein, Ms. Stone has also posed for Hugo ...