Parenting can be a lifelong exercise in patience. Just ask Heidi Klum.

In fact, the supermodel revealed that it may just be the biggest lesson her and ex-husband Seal's kids Leni, 19, Henry, 18, Johan, 16, and Lou, 13, have taught her.

"To be even more patient," Heidi told E! News exclusively on the red carpet of America's Got Talent season 18 finale Sept. 27. "To have even more patience than I had before."

Of her older teenagers, the 50-year-old added, "It's hard because when they're all driving around in their cars and you're constantly looking at the clock, 'When are they coming back?' It's nerve-wracking when they've become grownups and they just go off."

But despite the changing dynamics as her kids get older, Heidi shared there are some things she still relishes in doing for them. Like planning their birthday parties, for example.

"I mean, not like it used to be with bouncy houses and all of that stuff," the AGT judge noted. "But it's usually always in the backyard, now it's more like a hang. It's a hang."

Referring to Johan and Henry, respectively, she continued, "They have cool music and they're hanging. My son is turning 17 and my oldest son just turned 18. It's different, they hang now on their birthday. Their friends are coming over to hang."

But planning their parties isn't the only way Heidi celebrates her kids on their special days as she's no stranger to the sweet birthday shoutout on social media—complete with throwback baby pics.

"Henry Today you turn 18," she wrote on Instagram earlier this month, alongside a photo of herself giving her eldest son a bath when he was an infant. "HAPPY BIRTHDAY...Look how small you were and now you are 6"3 WOW...I LOVE YOU WITH ALL MY HEART."

And when her youngest officially become a teenager last October, Heidi shared a throwback pic of herself carrying Lou when she was a toddler, with both wearing leopard-print outfits and face paint.

"Happy 13 th Birthday Lou," she wrote. "I [love] you with all my heart."

To hear more from Heidi and other stars of America's Got Talent, watch E! News tonight at 11 p.m.

For the latest breaking news updates, click here to download the E! News App