We'll give you one hint: it's not Reese Witherspoon!
But it's actually the actress' look-alike daughter, Ava Phillippe!
[ Related: Reese & Ava Hang Out With Valentino ]
Celebrating her 16th birthday, Reese posted this adorable side-by-side to Instagram on Wednesday, captioning it:
"Wow! My sweet girl turns 16 today! 🎉🎂🎉I am so blessed to have such a kind, compassionate, brilliant, artistic, all-around wonderful daughter who makes me a better person everyday. I 💖you @avaphillippe"
We were honestly expecting a mention of how identical she and Ava looked. Seriously, she could have jokingly said "#Throwback Thursday" and we would have believed her!
Anyway, it's clear Reese and Ryan Phillippe's offspring isn't so little anymore!
Gah. They grow up so fast, don't they??
P.S. Check out Reese's throwback from The Man In The Moon (below) just to see how much she and Ava look alike!
[Image via Reese Witherspoon/Instagram.]
Tags: ava phillippe, celeb kidz, family, instagram, reese witherspoon, ryan phillippe