“What about Kate Moss?” Bessette asked. Klein hesitated. “She’s cute, but no one knows who she is.” Carolyn snapped, “Exactly. She’s almost unknowable. She’s guarded, elusive—she’s not trying to sell you anything or ham it up for the camera, she’s just letting you in.” Klein paused. “Well, let’s bring her in.” And just like that, according to ' 90s fashion lore , one “cool girl” gave rise to another. Carolyn Bessette ushered in Kate Moss, taking…