Beautiful women often have beautiful sisters, and beautiful celebrity women are no exception. Take, for example, Elizabeth Olsen, younger sister of the Olsen twins. She blew up at the Sundance Film Festival this year, and the Internet went crazy with talk of “the secret Olsen twin.” She’s in the news again now for her new film, Martha Marcy May Marlene, which got us thinking: how many other celebrity babes secretly have hot siblings? Turns out, a lot. Take, for example…

Monica Cruz

Yes, gentlemen: Penelope Cruz has a younger sister. While Monica may not be as famous as her older sibling, she does give Penelope one helluva run for her money in the looks department.

Marta Krupa

You know how Barbie comes in blonde and brunette varieties? Turns out, so does Joanna Krupa. Her sister Marta is the brown-haired beauty. How is this chick not famous?

Elizabeth Olsen

The Olsen twins aren’t exactly big-ticket items these days, but their younger sister, Elizabeth, is making a name for herself on the indie scene. She emerged at the Sundance Film Festival this past year and has a number of flicks lined up for the coming months.

Solange Knowles

Beyonce’s fashion-forward younger sister also sings. She also DJs at dancehalls. She also starred with Hayden Panettiere in the third Bring It On movie. Somehow, there are now five of those.

Casey Loza

The sister of Hills star Audrina Patridge and wife of motocross star Kyle Loza, Casey is like a tatted-up version of her celebutante sibling.

Sandra Vergara

Who knew Sofia Vergara, television’s favorite hot mom, had a younger sister? Pretty much nobody, until the above photo appeared in a popular men’s magazine a few months back.

Angel McCord

90210 star AnnaLynne McCord’s sister could pass for her twin in the right light. And we’re not sure how we feel about this, but the two have a tendency to publicly smooch. Each other.

Amy McCarthy

With that face, all Amy (left) has to do is throw on a revealing bikini and strike a seductive pose, and she could fool even the most diehard of Jenny McCarthy fans.

Pippa Middleton

Pippa is almost better known than her older sister, Kate Middleton, having stolen the spotlight at Kate’s wedding to Britain’s Prince William. Thus proving definitively that a celebrity’s hot younger sister is infinitely more interesting than any royal wedding.