We can't believe she's so grown up!

Kim and Kanye's daughter North turns 5-years-old today, and her reality star mom marked her birthday by posting some pics on social media! She even poked fun at Nori's diva behavior when it comes to her little brother Saint.

"My baby girl turns 5 today. Never did I think back then that I would have my best friend for life! I’m so honored to be your mom Northie! You have brought more joy into my world than I ever could have imagined. I can’t believe your so big now! The luckiest girl in the world to be best friends with your cousins and have the most magical parties together! I love you so much birthday girl! P.S. Now that you’re 5, don’t you think it’s the mature thing to try to be nice to your brother now!?!" she captioned one of the snapshots.

Fans are giving Kimmy K a little bit of a hard time for straightening North's hair, and some people think she even gave the little girl extensions! It's time to relax, everyone, this isn't a big deal.

The brunette bombshell had a fun night out with Kanye and pals Jonathan Cheban and LaLa Anthony last night at Nas' album listening party in NYC, so let's hope she has enough energy to run around the Big Apple with her oldest child today and celebrate the milestone!

Nas Listening Party @kimkardashian #kimkardashian

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