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

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,

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,

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 had a sweet birthday tribute for 12-year-old son Tennessee—whom she shares with ex Jim Toth—thanking him for making her "laugh everyday."