"Happy 6th Birthday Chicago! I honestly didn’t know too much about what raising a Capricorn girl would be like but you make it so easy and fun and silly!!!" the mom-of-four, 43, began her caption.
"I can already see the determination and ambition you have within you," the reality star continued about her and ex-husband Kanye West's third child. "You are so smart, sweet, silly and so lovable to everyone around you especially your cousins! It’s magical to see you all together and all the love that exists between the tribe."
"I love you so much Chi Chi and can’t believe you are 6 years old! I’m so so so happy to be your mommy!" Kim concluded.
While the upload pictured the mother-daughter duo at the annual Kardashian-Jenner Christmas Eve party last month, the SKIMS founder shared plenty of snaps and videos from the tot's Bratz doll-themed birthday party via Instagram Stories.
Many of Chicago's relatives paid tribute to her on her special day as well, with matriarch Kris Jenner honoring her via social media.
"Happy birthday to my angel pie Chi Chi!!!!! You are such a beautiful girl inside and out and your smile brightens everyone’s day!!!! You are the most amazing granddaughter, daughter, sister, cousin, niece, and friend and you are so kind, sweet, smart, creative, generous, loving and give the best hugs!" she gushed. "You are such a blessing in our lives my sweet girl and I love you to the moon and back ❣️💖💕💞💓 @kimkardashian."
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It's unclear if Kanye or his new wife, Bianca Censori, were at the party, though the couple was seen spending time with Chicago and some of her siblings last month.
After pictures of the outing made the rounds, many people on social media thought Censori looked just like the rapper's ex-wife — something many fans have voiced their opinion on in the past.