Heidi Klum and Seal's youngest child just hit a sweet milestone.
Lou Samuel turned 16 on Oct. 9, with her mom sharing family photos and videos taken through the years to mark the occasion.
One image showed a makeup-free Heidi posing with Lou and her siblings—Leni Klum, 21, Henry Samuel, 20, and Johan Samuel, 18—in front of a brick wall, while the group hit the beach together in another snapshot.
The supermodel also posted several throwback videos of Lou, including a sweet clip her fifth birthday celebrations.
"Lou my beautiful sunshine," Heidi, 52, wrote on Instagram. "Happy 16th Birthday. I love you with my whole heart."
But this month is more than just about celebrating Lou's birthday. After all, according to Heidi, she and the teenager are both huge fans of Halloween.
"Lou, especially. She makes her own things," the Project Runway host told People in 2024. "She's also really into anime. She makes all the wigs herself."
Heidi—who's known for her elaborate Halloween costumes—continued, "She's pretty talented, I have to say, more talented than me when it comes to building things."
"If anyone has the major block about dressing up and that stuff," the mom of four added, "it would be my Lou."
That would likely be why Lou was dressed to theme last month during her mom's inaugural HeidiFest in Germany, where the family celebrated Bavarian culture. Like her mom, the teen wore a dirndl—a traditional dress featuring a lace-up bodice and an apron skirt—and a flower crown.
"These are my roots—even if I'm not from Bavaria, I'm still German," Heidi said in a German interview with OK! magazine at the time. "I grew up here, too. And in that respect, I think it's nice for my children to see a bit of my roots."
To see more photos of Heidi and her kids at the event, read on.
Family First
Heidi Klum was joined by her and ex Seal's kids Leni Klum, Henry Samuel, Johan Samuel and Lou Klum at HeidiFest 2025 in Munich Sept. 18, 2025.
The supermodel also brought along her husband Tom Kaulitz, brother-in-law Bill Kaulitz and mom Erna Klum, as well as Henry's girlfriend Kayla Betulius to celebrate Bavarian culture.
Let's Eat
Heidi and Leni enjoyed a big German feast.
Dressed in Drindls
The supermodel and her daughter Lou wore drindls, a traditional dress featuring a lace-up bodice and an apron skirt.
Breaking Bread
Lou and Johan sat together at the family's table inside the Hofbräuhaus brewery.
Prost!
Leni and her boyfriend Aris Rachevsky shared a toast with large beer steins.