Vera Wang's daughter Josephine stuns in 30th birthday pictures

Vera Wang took to Instagram to share some rarely-seen snaps of her daughter Josephine to mark her 30th birthday.

"To my beautiful daughter Josephine. So thrilled to have celebrated your 30th birthday with you! I am so filled with pride," Wang captioned her Instagram post. 

The images feature Josephine in a stunning black mini dress with a plunging neckline, along with Vera and her ex-husband, Arthur Becker, and the former couple's eldest daughter, Cecilia.

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The comments on Wang's post quickly blew up, with over 300 users begging Wang and Josephine for the secret to their youthful beauty. 

"Genes are unreal," one amazed Instagram follower wrote.

"30?! I swear to god I thought she was 18 at first glance. She has your good aging genes! Congratulations 🎊 on both ur bday and good genes 😂," another user commented.

One added: "The Wang genes needs to be studied she freaking looks like 16."

The social media frenzy saw hundreds commenting on Wang's "incredible genes", while a select few took it upon themselves to remind the masses that her children are actually adopted.

"Her kids are adopted. But Vera is ageless, yes," said one user in response to a comment on the family's genetics. 

"Oops it must be just be her energy," responded the original commenter. 

Wang and Becker adopted both their daughters and have maintained close relationships with them since their marriage ended in 2012.

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Some famous names also took the opportunity to wish the designer's youngest a happy birthday.

Actress Sharon Stone commented, "30 !!!! Omg I DIDN'T recognize Arthur What's going on Our kids are adults We've known each other literal lifetimes."

Even Vera herself wrote a sneaky line in the comments section, joking that her daughter was, "wearing MOM of course!!!"