Kailyn Lowry can't believe how far his son has come.
The former Teen Mom star had a special milestone to celebrate when her oldest child Isaac turned 13 on Jan. 18.
"We have literally grown up together, but in some ways he's even more grown than I am," Kailyn wrote on Instagram. "Thoughtful, brilliant, funny and at times a smartass are a few words I would use to describe Isaac. I think what really inspires me about him is the way he challenges social norms."
Kailyn described her son, who she shares with ex-boyfriend Jo Rivera, as curious, open-minded and someone who "can form his own thoughts and opinions."
"Isaac also accepts people for who they are and never how they're ‘supposed' to be," Kailyn continued. "More people should be like him."
Kailyn, who also shares Lincoln, 9, with ex Javi Marroquin, as well as Lux, 5, and Creed, 2, with ex Chris Lopez, treated her oldest to dessert from Baked'Em Bakery in Delaware and a birthday setup from The Party Kween.
Before heading off to school, Isaac shared his own message of gratitude to his family for all they have done.
"Thank you, to my parents for everything," he wrote on Instagram. "For the care, for the love and just being in my life in the first place. Even through the hard times, you've been there. You'll never know how happy you made me today, and everyday."
"To all of my siblings, thank you too," Isaac continued. "We may complain about each other, but at the end of the day, we're still family. I love all of you! Same goes to the rest of my family. I wouldn't have made it without any of you. We may not be able to see each other often, but you'll always have a special place in my heart."
Kailyn first appeared on MTV's 16 and Pregnant in April 2010 where she documented her birth to Isaac. She was later selected to appear on Teen Mom 2, where she continued to share her life as a mom.
In May 2022, Kailyn announced she was leaving the franchise after 11 years to spend time on other ventures.
"I want to focus on my self-growth and my kids and I didn't feel like the show aligned with the goals that I have anymore," she exclusively told E! News at the time. "I decided it was time for me to move on."
Since leaving the show, Kailyn has remained friendly with members of the Teen Mom family. In fact, Tyler Baltierra was one of the many close friends who couldn't help but celebrate Isaac's big day on Kailyn's latest Instagram post.
"He's just as blessed to have you as his mother as you are to have him as your son!" he wrote in the comment section. "You're doing such an amazing job raising him & all of your boys Kail. The bond between mother & son is unexplainably profound! I'm proud of you for the life you've given your kids."