Heidi Klum Shares Behind-the-Scenes Look at Daughter Leni's 20th Birthday Celebrations: 'Time Flies'

Heidi Klum is celebrating her daughter Leni's birthday in style!

On May 4, the supermodel, 50, shared a series of highlights on Instagram of Leni's 20th birthday festivities — including some behind-the-scenes videos that appeared to be of a photo shoot in progress.

In one video, the mom of four — sporting a casual outfit including jeans and a neon yellow jacket — can be seen directing traffic as Leni and a big group of friends cross a city street together and throw up some peace signs for the camera.

Another post features two photos of a big group of Leni's friends sticking out their tongues and smiling at the camera for a selfie, taken by Heidi.

"Birthday crew 🥳❤️ for Leni 🌸," the proud mom captioned the photos.

Yet another video shows Leni wearing a pink and white top with a heart embellishment and the message, "You totally can have your cake and eat it too," a fluffy pink skirt and a large pink bow on the top of her head. The young model dances around the room — which is filled with racks of clothing and people bustling around, seemingly for a photo shoot — to the music of "Riverdance."

"This is 20 🥳 LENI ❤️," Heidi wrote in the caption.

Leni shared her own videos of her fun-filled birthday on her Instagram Stories, including one of her very pink outfit, and several selfies featuring her mom and some friends.

Putting aside the high-energy birthday party feel of her other posts, Heidi shared one more heartfelt Instagram post offering a look back at Leni's childhood. In the sweet video, the model can be seen holding Leni — then just a few months old — as the pair floated in the ocean together.

"Can you say, 'I love you?' " Heidi can be heard telling Leni in the clip, kissing her on the cheek.

"Happy 20th Birthday Leni Olumi," she wrote in the caption of the birthday tribute. "Time flies. This feels like it was just yesterday. I love you with all my heart. Keep shining your beautiful light."

Leni is Heidi's oldest child. She shares the 20-year-old with her ex, Italian businessman Flavio Briatore, but her ex-husband Seal adopted Leni after he married Heidi. Leni is also a big sister to Heidi and Seal's sons Henry Günther and Johan Riley and daughter Lou Sulola.

Heidi and Leni have always been candid about their close mother-daughter relationship. Last year, the former Victoria's Secret angel spoke to PEOPLE at the 2023 Nickelodeon Kids' Choice Awards about just how proud she is of her daughter for pursuing school and modeling at the same time.

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"I'm very proud of my daughter and her modeling," she said at the time. "And she's studying at the same time, she's juggling already."

Leni previously spoke to PEOPLE about making her modeling debut alongside her famous mom on the cover of Vogue Germany in 2021.

"I've always gone to work with my mom and thought, 'This looks so fun. She looks so happy while she's working,' " Leni said in 2021. "I'd jump in sometimes, and I'd play around with the makeup that her makeup artist would bring."

"That's, like, insane that I did that as my first job and my mom was with me, which made it so much fun. It was just such a good day," she added, noting that her first-ever job as a professional model was on the cover of Vogue. "I wasn't nervous at all. I was just so excited. I was like, 'I'm finally modeling, and it's Vogue.' It was just so many things to be excited about."