Reese Witherspoon's youngest child is officially a preteen — and she celebrated by sharing a rare photo of her lookalike son.

It's a big day for Reese Witherspoon's youngest son, Tennessee, who celebrated turning 12 years old. Of course, Witherspoon posted a sweet message to commemorate the milestone—a

Reese Witherspoon shared a sentimental birthday tribute to her youngest son Tennessee James, whom she shares with ex-husband Jim Toth, on Instagram on Sept. 27. Tennessee's siblings, Ava and Deacon Phillippe,

Reese Witherspoon is proudly celebrating her youngest son Tennessee’s birthday with a special message. “Happy 12th Birthday to my wonderful son, Tenn! ,” Witherspoon, 48, gushed via Instagram on Friday,

Legally Blonde star Reese Witherspoon is a mom of three, sharing Ava and Deacon with ex Ryan Philippe, and her youngest son Tennessee with ex Jim Toth

The Legally Blonde actress' youngest son, Tennessee James Toth, has officially marked his final year before he reaches his teens. His proud mother marked the occasion with a rare photo of her youngest child, whom she shares with ex-husband Jim Toth.