Reese Witherspoon took to Instagram over the weekend to wish her daughter Ava a happy 18th birthday.

"Happy 18th Birthday to my sweet girl @avaphillippe ! Your kindness, grace, intelligence and humor never cease to amaze me. I love you and your HUGE [heart] and I feel so lucky that I get to be your mom. #proudmom #18," the Oscar-winning actress captioned a throwback photo of her smiling and hugging Ava when she was a little girl.

Witherspoon also posted a more recent portrait of her daughter with the simple message, "#18."

Ava's dad, Shooter actor Ryan Phillippe, also recognized her milestone birthday on Instagram.

"Happy birthday, punk. i love you more than any strangers need read, but..." he wrote alongside an old outdoor photo of the two of them, followed by other highlights from their family album.

"You are the coolest, smartest, most beautiful daughter a father could ever have, and even though you're no longer a child, you'll always be my little girl. happy 18th, princess," he captioned a series of snapshots of her through the years.

Ava's birthday was Saturday and her father turned 42 Sunday.

Witherspoon and Phillippe were married from 1999 to 2007. They also have a 13-year-old son named Deacon.