Sienna Miller's First-Ever Instagram Post Is So Cute

Better late than never: Sienna Miller has officially posted her very first Instagram. Thanks to Cara Delevingne, who shared Miller's handle along with a cute selfie, we learned that the chic Brit just got her own account. So how did she commemorate the occasion? Clad in Dior's now-iconic We Should All Be Feminists T-Shirt ($710), Miller posted a cute photo with the word "greetings" written on her hands.

She also acknowledged the fact that she's a bit late to the game with some funny hashtags: "Hello World Wide Web," she captioned the post. "#givenin #peerpressure #luddite." If you love Miller's style as much as we do, you should probably start following her pronto—she's already racked up 39,000 followers in just 24 hours. Impressive, right?

Scroll down to see Sienna Miller's first-ever Instagram post and to shop her T-shirt.