While most 13 year olds might be scoping crushes at the mall and talking loudly on their cell phones for hours on end, Elle Fanning is upping the ante. Little sister to actress Dakota, Elle skips past the whole awkward kid-to-young-adult clothing phase as the new face of Marc by Marc Jacobs. The new ad campaign, for fall 2011, just debuted and the blonde beauty looks a complete natural for the collection. Look out tweens, life just got a little toug...