Gwyneth Paltrow is one of the most famous and highest earning actresses in the world, but when she's not on set, the 47-year-old tries to maintain a relatively low profile and keep details of her personal life out of the spotlight.
She rarely posts about her kids on social media - the Oscar winner has two children with ex-husband and Coldplay frontman Chris Martin - Apple, 16, and Moses, 14.
But Gwyneth decide to make an exception for a very special occasion - her daughter Apple's 16th birthday - penning a heartwarming tribute to her eldest child on Instagram, alongside three gorgeous new photos.
"I can't believe I'm actually writing these words but... happy sweet sixteen my darling girl," Gwyneth wrote.
"You are the light of my heart, you are pure joy. You are wickedly intelligent and you have the best, most dry, most brilliant sense of humour. I have the best time being your mum.
"I love our nightly evening chats when I really get to hear what's on your mind. You work hard to get whatever it is you want to achieve, and you have grit and responsibility in spades. I am so damn lucky to be your mother, you beautiful, kind young woman. Thank you for choosing me.
"I adore you to the moon and back a zillion times. I'm sorry you are having this particular birthday during these circumstances, but as always with you, you find the best in everything."
Gwyneth's fans took to the comments section on the post to wish Apple a happy birthday and remarked on how quickly the teenager has grown up.
"Happy happy birthday! How can she be sixteen? She's beautiful!" one fan wrote.
Actress Kate Bosworth commented: "Oh my gosh, I cannot believe she is 16! What a gorgeous, bright spirit."
Another fan said, "Dying that she is 16, what a beautiful tribute from the most kick ass mum to date".
Other fans could not get over the visual similarities between the mother and daughter.
"Happy 16th birthday, you both are like twins!" one Instagram follower comments.
"Gosh she looks like if you and Chris Martin had a baby or something! She's beautiful! Apple doesn't fall far from the tree. Gorgeous," another fan joked.
"She is a young Gwyneth, beautiful girl," another said.
And this fan joked: "I wonder how many times a day you hear 'the apple doesn't falll from from the tree'. She looks so much like you! Happy Birthday Apple."
Gwyneth, the founder of lifestyle brand Goop, recently shared a hilarious story about Apple that any parent of teens will be able to relate to.
"My daughter finds me mortifying," the Shakespeare in Love star told guest host John Legend on Ellen DeGeneres' talk show back in February.
"If I do anything in public past not talking and standing still, she's like [mouthing 'Stop!'] If I dance she turns red."
She also revealed that her daughter is learning to drive - and Gwyneth described an incident in the car that made her feel as though she had "failed as a mother".
"She [Apple] went through a red light and I kind of yelled at her and then she started crying and it was just terrible and I felt so bad," Gwyneth revealed.
"So then I was like, 'Ok, you know what, I'm just going to be chill,' and you know what, she's now an amazing driver and I think I've learned from my mistakes."
WATCH BELOW: Inside Gwyneth Paltrow's romance with husband Brad Falchuk.
And aside from the visual comparisons, Gwyneth says her daughter is also starting to take on some of her personality traits.
"What's funny about kids is you can see how they start to take on certain aspects of you, like I kind of have road rage in the car, and she does too," Gwyneth said.
Gwyneth and Chris Martin "consciously uncoupled" back in 2016. Since their split, both have found love again.
Gwyneth is married to producer and writer Brad Falchuk and Chris is currently dating his on-and-off girlfriend Dakota Johnson.