on Saturday, Kim posted a handful of pics and videos to honor the birthday girl.
The first snap was a close up selfie of Kim and Chicago, which was followed by a video of Chicago and her brother Psalm, two, discussing superheroes.
More videos captured Chicago spending time with her family members as she sang her ABCs and pursed her lips alongside Kim.
The Keeping Up with the Kardashians alum shared even more photos with Chicago, while the final photo captured Kim posing with all four of her kids on the beach.
Alongside the photos and videos, Kim wrote: “My birthday baby girl Chi Chi turns 4 today!
“My independent baby girl twin.
“You are the most lovable huggable snuggable baby girl on the planet. The ultimate princess!”
She continued: “I can’t wait to celebrate with all of the Barbies and LOL Dolls a girl could dream of lol.
“You really have brought so much joy into our family and I love you so so soooo much!!!!”
Shortly after Kim shared the post, a number of her friends and Instagram followers took to the comments section to wish Chicago a happy birthday.
In addition to Chicago and Psalm, Kim shares kids North, eight, and Saint, six, with ex-husband Kanye West, 44.
KANYE CALLS OUT PETE
Kim celebrated Chicago's birthday shortly after her ex called out her new boyfriend Pete Davidson, 28.
On Friday, Kanye released a new song called Eazy with The Game.
The rapper threw shade at the Saturday Night Live star as he rapped: "God saved me from the crash, just so I can beat Pete Davidson's a**.”
Pete wasn't the only person Kanye targeted in the song, as he also hinted he doesn't approve of some of Kim's parenting decisions.
KIM'S NEW MAN
After first being romantically linked in late October, Kim and Pete's romance seems to be getting serious.
The pair were spotted packing on the PDA during a pizza and ice cream date night this week in Los Angeles.
The Sun exclusively reported the pair were caught getting comfortable with each other during a secret date at an L.A. restaurant.
They were spotted holding hands and hugging each other tightly inside Jon & Vinny's Italian restaurant.
A fellow diner told The Sun: “They were there around 8pm (Tuesday) night. Just the two of them. Corner booth.
"Him facing out to the restaurant and her facing just him. They were kissing at their table."
He added: "They were definitely intimate and leaning into each other during the date.”
Following the dinner, the power couple stopped by a local Rite-Aid Pharmacy for some Thrifty brand ice cream.
Kim's daughter North shows off new blond braids and braces in TikTok