And she looked tres chic, in an adorable navy midi dress that channeled classic storybook style with a grown-up twist. The exact dress Lacey wore was the from luxury designer Rebecca Vallance. The magic of Lacey's dress lies in its oversized white bow, which strikes the perfect balance between sweet and sophisticated. Add to Google settingsPlus, Lacey’s dress is embellished with pearls for the ultimate fairytale effect (they’re not imprinted polka dots)—and the look will cost you. Though the Rebecca Vallance dress is currently on sale at Saks Fifth Avenue, but it’ll still set you back $600.