“Is there any bigger affront to the most stylish 14-year-old girl in Hollywood than having to wear a kilt to school? Done in a traditional tartan, it’s part of the uniform at Campbell Hall, Elle Fanning’s private school in the San Fernando Valley, where it’s paired with a polo or blouse in white and navy (seniors may add two colors) and a navy overcoat (all jackets, including hoodies, must be navy). Fanning—co-star of films like Super 8, We Bought a Zoo, and the upcoming BFF-betrayal indie Ginger & Rosa—likes to wear her skirt short, but not too short, on her “five-seven-and-three-quarters” frame, and who’s to say what’s short anyway? “The kilt’s supposed to be long enough that your fingertips can reach the ends [when you’re standing]. But what if someone has extra-long or extra-short arms?” she says, giggling.

At home, Fanning keeps her Campbell Hall clothes separate from her going-out clothes, things like Prada geisha shoes, loose Céline pants, and floor-sweeping dresses by the Rodarte sisters, for whom she has been a muse. “I have a sliding glass door on my closet,” she says, “and when I slide it one way I can see all my uniforms, and the other way is all my own clothes.” And, of course, she can make a kilt work if she has to. Today, arriving at the cozy, buttercream-scented headquarters of Duff’s Cakemix, a “cake-decorating studio” in Hollywood, she’s accessorized with maroon Alexander McQueen ballet flats with a brass skull medallion at the toe (a tweak on conservative staples like Tory Burch’s), a stack of diamond and ruby rings (loaded up on her ring finger like a middle-aged woman’s anniversary bands), and two gold chains. “I like necklaces that are short, the way skateboarders used to wear them in the seventies,” she says, touching the one that hangs a bit lower than the other on her alabaster neck.”