Reese, who shares Ava with former husband and fellow actor, Ryan Phillippe, welcomed her first child back in 1999 - an event which Reese insists changed her for the better.
In honour of her eldest child, the doting mum-of-three took to Instagram and paid tribute to the beautiful young woman who shares every one of her mum's stunning looks.
Like most mums, Reese admits she struggles with the speed with which the years pass, writing; "Wow! My sweet girl turns 16 today!"
In a heartfelt message to her first-born, the Walk the Line star wrote: "I am so blessed to have such a kind, compassionate, brilliant, artistic, all-around wonderful daughter who makes me a better person everyday."
Telling Ava she loved her, the star then shared a throwback snap of her daughter alongside a current snap of the lovely Ava.
Commenting on the star's striking resemblance with her teen daughter, one astounded fan wrote: "I actually thought it was her on the right and the little kid was her daughter!! Image!!"
Sharing her thoughts on the touching upload, another fan exclaimed: "She looks just like you! I mean you could almost be twins!"
We couldn't agree more!
