Kate and Jon Gosselin Share Birthday Messages for Sextuplets on Their 13th Birthday

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Kate and Jon Gosselin's sextuplets are officially teenagers!

On Wednesday, mom Kate shared a sweet birthday message for Alexis, Hannah, Aaden, Collin, Leah and Joel, where she reminisced about giving birth to six babies at once.

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The Kate Plus 8 star accompanied the post with a collage featuring then-and-now photos of the sextuplets.

"At this moment (7:51-7:53 am) 13 years ago, my life and heart were completed with your births!," she recalled. "I love you all and NO MATTER WHAT it requires of me, I will ALWAYS be there for you."

"I'll always be your biggest cheerleader, your role model by example, your shoulder to cry on, the hug and laugh you need, and your mommy and friend!," continued Kate. "I love you guys! I got six times what I planned on, but I'd NEVER EVER go back! You're the six final pieces of my heart that I never knew I was looking for."

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Kate's ex-husband, Jon, started the birthday celebration a little early. The proud dad took to Instagram on Tuesday with a photo of a birthday cake.

"I can't believe my little kids will be 13 tomorrow!!!," he gushed. "Happy Birthday Hannah, Leah, Alexis, Aaden, Joel and Collin."

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While fans have watched the sextuplets and their 16-year-old twin sisters, Mady and Cara, grow up in front of the camera, being on TV isn't always easy.

In December, Kate, whose tumultuous relationship with Jon has played out in the press, admitted to making parenting mistakes.

"I mess up, yet it's out of love for my kids that I say, 'I messed up. I need to get better at that,'" she confessed during an episode of the Dr. Oz Show. "I mean, my life is my kids and there just wouldn't be Kate Gosselin if it wasn't for my kids. Everything I do [is] for them. I mean, being on TV is not easy. Having tabloids written about you constantly is not easy."

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