Reese Witherspoon has nothing but love for her big brother.

The "Legally Blonde" actress took to Instagram on Wednesday to share a sweet message and photo for brother John Witherspoon ahead of a milestone birthday.

"Happy 50th birthday to my big Bro John!!" she wrote in the caption of the post. "Thank you for teaching me how to change a flat tire, skip rocks on the lake, build a fort in the backyard and catch so many frogs."

"You always make life an adventure!" the Oscar winner and "Big Little Lies" star, 46, continued. "I love you Brother."

In the photo -- a rare family snap -- the siblings are seen sitting beside each other all dressed up at a restaurant.

Witherspoon also celebrated mom Betty Reese's birthday recently, sharing a tribute fit for "the most amazing Mama in the whole world."

"Every day I get to hear you laugh while you tell the best stories is such a gift," she wrote. "Please keep bringing sunshine into our lives."