Duchess of Cambridge Kate Middleton and her suddenly-famous younger sister Pippa may be best friends, but that doesn't mean they're unlike most siblings.

"There is a healthy competition between the two," royal watcher Katie Nicholl tells Us. "Certainly when it comes to looks, there is a little friendly rivalry."

Posted in: Kate Middleton

Pippa Middleton Biography

Prince Harry and Pippa Middleton Pippa Middleton is the sister of Kate Middleton. Kate married Prince William in April 2011, but it's her younger sister who's getting... More »
Full Name
Pippa Middleton