It's hard to keep up with how quickly Kim Kardashian and Khloe Kardashian's daughters are growing up. 

In a new Instagram photo shared by the SKIMS founder, Kim and Khloe's children appear to enjoy a spring break by the beach, and in one photo, the Kardashian sisters' daughters, True and North, are practically teenagers. 

The first pic in Kim's April 8 Instagram post, aptly captioned, "spring break," shows North, 10, posing with True, who will turn 6 April 12, on her back. The eldest Kardashian-West is donning a simple gray T-shirt with her hair in two half-pigtails. Meanwhile, True wears a white floral tank top with her hair in partially purple braids. 

It appears the family celebrated True's upcoming birthday during their time off, as the last slide of Kim's post includes a pink balloon sign reading, "Happy Birthday True." Other highlights include a sightseeing boat ride to see dolphins and time at the beach. 

Kim's other children Saint, 8, Chicago, 6, and Psalm, 4—whom the 43-year-old shares with former husband Kanye West—as well as Khloe and Tristan Thompson's son Tatum, 20 months—joined in on the trip. (While Tatum wasn't included in Kim's post, he was featured in one of Khloe's posts from April 6.)

And Kim and Khloe's eldest children not only look grown up—they're also coming into their own. After all, North has leapt into a music career with a feature on her father's latest disc Vultures, and even teased her own album, Elementary School Dropout, during one of Kanye's listening parties for the Vultures 2 record back in March. 

As she told the crowd at a March 10 show in Phoenix, Arizona, "I've been working on an album."

Meanwhile, Khloe also shared another grown-up update of True, Chicago, and brother Rob Kardashian's daughter Dream celebrating Easter together on April 1. 

Read on for more sweet moments from the Kardashians' kids.

True Thompson and Chicago West honor their respective mothers, Khloe Kardashian and Kim Kardashian, in a mischievous way.

True and Chicago share a sweet moment.

True and Psalm West wear casts after breaking their arm in August 2023.

Khloe's daughter and Rob Kardashian's daughter Dream Kardashian pose for pics for St. Patrick's Day 2023.

Khloe shared this photo of her daughter True, plus cousins Penelope Disick, Saint West, North West, Reign Disick, Psalm West and Dream in February 2023. She wrote, "This photo was near a miracle to get lol...a handful of other other cousins were off running and playing."

Penelope Disick, North West, Dream Kardashian and True Thompson appear together in February 2023.

Chicago sings her dad Kanye West and XXXTENTACION's song "True Love" while sitting in a vehicle with her little brother Psalm West in October 2022...

...the song references his and Kim Kardashian's four children, but Chicago and Psalm did not perform those parts.

Khloe and True have Dream over for a sleepover in June 2023.

Kylie Jenner, Stormi Webster and Kris Jenner lip-synch one of the momager's confessional lines from The Kardashians in an October 2022 TikTok video.

In August 2022, Kim coined the acronym "best friends forever and ever" to describe True, Chicago and Dream.

Penelope Disick helps North West celebrate her 9th birthday with a "Camp North"-themed getaway to the wilderness with a group of BFFs.

"Today was incredible! Our girls had their first dance recital and they were perfection!!!!" Khloe shared in June 2022. "I am so proud of all four of my girls!"

The cousins celebrate True Thompson's fourth birthday during a cat-themed bash in April 2022.

Penelope and North snap a video during True's birthday party.

Psalm accompanies True while playing with a furry friend.

The cousins pal around in a play pen.

True and Dream have an epic dance party to Aqua's '90 hit song "Barbie Girl," which Khloe documented on Instagram.

The BFFs also performed and sang along to the massively popular song from Encanto "We Don't Talk About Bruno."

Could their dance moves be any cuter?!

Chicago, True and Stormi give each other hugs and kisses in an adorable pic, shared by Kim on Sept. 1. "250 Million followers on IG. I love you guys!" Kim thanked her fans. "I wanted to post this pic because if I could get 250 million kisses from our babies my life would be complete." 

Chicago, True and Stormi showed off their fashion prowess in stylish outfits as they had a hug huddle on Sept. 1. 

Chicago looks back at aunt Khloe as she holds hands with True on Aug. 4. 

Dream, Stormi, Chicago and True adorably went window shopping at The Grove on Aug. 4. "Cousins," Khloe captioned with a purple heart emoji.

Reign, Mason, Penelope and North set up a summer lemonade stand also selling custom bracelets on Aug. 1. Even Scott received a custom "Lord" bracelet from "pooshalini" Penelope!

"The sweetest girls," Khloe Kardashian captioned a precious moment between cousins Dream Kardashian, True Thompson and Chicago West. 

Former E! star Natalie Halcro's daughter also joins the photo opp. 

Dream, True and Chicago sport matching purple leotards.

"Are you ready for this cuteness?? I'm not!! #Cousins #Sisters #GirlsRunTheWorld," proud mom (and aunt) Khloe captioned an adorable pic of daughter True and nieces Chicago and Dream.

Chicago, True and Dream all gaze in the camera for a pic in May 2021. The trio of cousins seem to be having fun in the sun and enjoying the spring weather!