Candace Cameron Bure shares birthday tribute to son: 'How is my baby so big?!'

/ Source: TODAY

It seems like just yesterday that we were following D.J. Tanner's high school years on "Full House" — but now Candace Cameron Bure has three teenage kids of her own.

The proud mom took to Instagram Friday to wish her youngest child, Maksim, a happy 15th birthday, with a photo that shows the tall teen towering over her.

"How is my baby so big?!" Bure wrote.

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Earlier in the day, the 40-year-old "Fuller House" star shared another cute mother-son pic, with a heartfelt message.

"Always keep your smile and joyful spirit, it's what sets you apart," she captioned the photo. "I'm so grateful God made me your mom. I love you Maksim!!"

Bure has another son, 16-year-old Lev, and a daughter, 18-year-old Natasha — who appeared on "The Voice" this past fall — with Valeri Bure, her husband of more than 20 years.

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The actress has plenty of reasons to celebrate these days. She and her co-stars recently announced that "Fuller House" will return to Netflix for a third season in 2017.

To find out how Candace and Valeri met, watch this TODAY flashback from 2007: