You might know that Reese Witherspoon has three kids.
But did you know that Reese's eldest, Ava, is now 18?
Reese celebrated Ava's birthday by posting this adorable photo on Instagram:
The caption says:
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 and I feel so lucky that I get to be your mom. #proudmom #18