Thomas Rhett's little girls are growing up: Believe it or not, there's officially no longer a baby in the house!

The singer's youngest daughter, Lillie Carolina, officially crossed the baby-to-toddler milestone, celebrating her second birthday on Wednesday (Nov. 15).

On his social media, Rhett posted a carousel of photos celebrating Lillie on her birthday, including a photo of the birthday girl surrounded by colorful, festive decor on her big day. Balloons, wrapped presents and a birthday banner with a daisy chain are just some of the elements of Lillie's birthday celebration.

Other photos show snapshots from Lillie's life so far: They show her hanging out on the beach with her dad, cuddling with her mom as a newborn and everything in between.

In the caption of his post, Rhett admits that he's pretty flabbergasted at how fast she and the rest of his daughters are growing up.

"Lillie how in the world are you two already??!" Rhett writes. "Time is moving so fast. I love you sweet baby. You bing so much joy with that smile of yours. HAPPY Birthday!!!"

Lillie is the youngest of the four daughters that Rhett shares with his wife, Lauren Akins. They're also parents to 8-year-old Willa Gray, 6-year-old Ada James and 3-year-old Lennon Love.

PICTURES: See Inside Thomas Rhett's $4.7 Million Rural Paradise

When Thomas Rhett and his wife, Lauren Akins, want to get away from it all, they sure have plenty of space and privacy. The couple and their kids can relax and unwind as much as they'd like at their rural weekend retreat outside of Nashville, which features an amazing barn-themed house that is a perfect home away from home.

Gallery Credit: Sterling Whitaker

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