A-lister Reese Witherspoon can’t believe her daughter Ava Phillippe is already 20 years old — and neither can we! Taking to Instagram on Monday, September 9, the mom of three, 43, shared two pics of the young model, one as a little girl and the next as an adult, to commemorate her birthday.

“Watching your little girl grow into a gorgeous, thoughtful, compassionate, fun-loving young woman defies words,” she penned in the caption. “It has got to be the greatest gift I could ever receive. I love you @avaphillippe to the moon, around the stars and back! Happy 20th! 🎂✨💖.”

In the comments section, Ava thanked her mom for the sweet shout-out. “Love you so much, mama,” she wrote.

Reese’s friends had a lot to say about the beautiful tribute. “Happy birthday! Can’t believe she 20 🙌AMAZING!,” Kate Hudson added. Katie Couric, on the other hand, shared two spinning heart emojis.

Along with Ava, Reese shares 15-year-old son Deacon Phillippe with ex-husband Ryan Phillippe and she is also raising her 6-year-old son, Tennessee Toth, with husband Jim Toth.

“My mothering personality is nothing like my work personality,” the Legally Blonde star admitted to InStyle in May. “I melt around my kids. I’m much more squishy, soft, and lovey with a caramel center.”

Reese Witherspoon

Not only that, but Reese also likes to make sure her kids are given as many advantages as possible in life. “As a teenager, you only know what you know in the world. You don’t know what it’s like to work in a foreign country or to be in medicine or science,” she said. “I have friends in a lot of different fields, so I try to surround my kids with people who have incredible experiences in other industries. We can get really isolated here in Hollywood.”

Ava is just as beautiful as mom Reese — on the inside as well as the outside!