The 39-year-old actress took to Instagram posting a stunning then-and-now side-by-side shot of her eldest sweet 16th.
"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 [love] you @avaphillipe," Reese proudly captioned the sweet split shot of her daughter.
Ava is the eldest of Reese and ex-husband Ryan Phillippe's two children. They also share a son, Deacon, 11.
The teen is also the older sister to her half-brother, Tennessee, two, from her mum's second marriage to Jim Toth and 4-year-old Kai, form her dad's relationship with Alexis Knapp.
We have to say, young Ava is the spitting image of her mother! Honestly, the pair could be mistaken for twins.
Shortly after tying the knot, Reese was just 23-years-old when she had Ava, with Ryan.
"I didn't know what I was doing. I was young. It was shocking. When people ask, 'When's the best time to get pregnant?' I say, 'Pick the best day for when your entire life is gonna change.' There's no good time to have your world turned upside down," she joked to Glamour last December.
"Seeing my kids for the first time was primal. The ferocity of love you feel for your children when you see them for the first time—but you've known them inside you—is phenomenal."
The protective mama bear also added that she hopes by the time Ava graduates high school, she’d have taught her “to not be ashamed about any of her experiences. To live life fully, with curiosity and love, and to be brave."
It looks Reese is certainly leading by example. The mum-of-three had the opportunity last year to take Ava to the Kakuma refugee camp in Kenya.
“It was like nothing I’d ever witnessed before,” Reese recalled, before adding the experience was profound for her daughter.
She gained “consciousness, awareness, hopefully a feeling of wanting to give back.”
“She’s a wonderful socially conscious girl but even a kid that reads a million books about a situation, you don’t understand it until you see it for yourself,” Reese mused.
“She didn’t say a word the whole day and didn’t even talk about it until a couple of days later,” Reese said.
With such a fabulous role model, we foresee great things for birthday girl, Ava!