1. Paris and Nicky Hilton
These girls have been stylish since the womb and they're not showing any signs of stopping anytime soon.
2. The Kardashians
Have you seen their closets?! 'Nuff said.
3. Tia and Tamara Mowry
The original Sister, Sister duo—with good taste.
4. Kate and Rooney Mara
These sibs take chic to another level.
5. Mary-Kate and Ashley Olsen
There's just no stopping them.
6. Kendall and Kylie Jenner
The Jenner gals know the fashion industry inside and out.
7. Zooey and Emily Deschanel
Just like the acting gene, style smarts must run in the Deschanel family.
8. Solange and Beyonce
Of course Beyonce and Solange would make it to the front row of fashion week. They dress the part.
9. Francesca and Morgan Eastwood
Being their sis would be a wardrobe dream come true.
10. Jessica and Ashlee Simpson
The Simpson girls are front-runners in the sisterly fashion competition.
11. Hilary and Haylie Duff
Hilary and Haylie Duff starred in a movie where they played sisters and fashionistas. Appropriate, right?