That's because the celebration doubled as a Destiny's Child reunion with Rowland's bandmates Beyoncé and Michelle Williams.
Sure, the ladies have been busy pursuing their solo careers, but judging by their adorable photo booth snaps, you'd never guess their bond has changed since they got "Bootylicious" in 2001.
Rowland shared a handful of images via Instagram on Sunday, showing the musicians striking poses together and Rowland getting cute with Williams.
Beyoncé's mom Tina Knowles Lawson also got in on the fun, joining the DC women plus husband Richard Lawson and daughter Solange and Rowland for even more photos. "We look like members of The Addams Family," the matriarch wrote of one Instagram featuring Bey.
In a sweet tribute to Rowland, Knowles Lawson wrote, "Could Kelly be more beautiful," topping off the caption with a heart emoji.
On Feb. 11, Rowland's actual birthday, her proud husband Tim Weatherspoon recognized Rowland's many roles in an Instagram post showing the couple with their son Titan, 15 months.
He wrote, "Today we celebrate the wife, mother, sister, aunt, friend, dreamer, giver, talented, compassionate, strong, sweetest, goofy, loving, beautiful, selfless Kelly. The world is a better place because you're in it. Keep Shining!! Happy Birthday my G!"
In addition to celebrating new milestones with their little one – Titan is already learning Spanish! – Rowland has been gearing up for her next album and BET reality-singing competition Chasing Destiny.
She told PEOPLE earlier this month, "I'm pretty busy these days, but I love it."