When we constantly see our favorite celebrities step into the spotlight on their own, it's easy to forget that they actually have sisters and brothers. So whenever we hear that stars like Jennifer Lopez or Sofia Vergara have younger siblings (we kid you not), we just shake our heads and marvel at the fact that we never even knew they existed.

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A lot of these famous younger relatives have gone to great lengths to prove that they can be just as successful as their superstar siblings. For instance, Penélope Cruz's little sister, Mónica, is an amazing dancer and actress just like her sister. But you know what's truly intriguing? The fact that they never let their popularity or level of success affect their sisterly bond!

"I have been raised to value my family. Penélope and I never fight, we have a really, really good relationship. It makes me angry and sad when people ask if we argue because I can't imagine a family being any other way," she said.

When Mónica was asked whether or not she ever felt like she was stuck in her sister's shadow, she didn't hesitate to come to her sister's defense.

"No, we are all individuals. Penélope was hyperactive… The other day we were looking at some home videos of us as children and Penélope was always the clown – acting, singing, fooling around – and I would just be sitting there looking at her. Just quietly sitting staring at my big sister," she said.

Talk about adorable! This tight-knit relationship that they have is pretty evident whenever we see them posing together, and we can also say the same for these other stars who have younger siblings!

Check out our gallery to see other celebrities you never realized have a younger sister or brother.