Belle Delphine is a UK based cosplayer, model, and social media personality who rose to fame due to her many photographs of her dressed in cosplay while performing an ahegao face. While she definitely looks way too young, she was born on October 23, 1999, which makes her 19-years-old.
While Belle has been posting to Instagram since 2015, she didn't start to get noticed until she posted this one on September 10, 2018. According to Know Your Meme, the post received over 35,000 likes in just over two months.
Just recently, she followed through on a promise she made and created a Pornhub account after one of her Instagram pictures received over 1-million likes.
From there on, she kept posting more and more cosplays featuring the ahegao face including this one dressed as D.Va from the popular video game, Overwatch.
Here she is dressed as Bowsette, the ever-popular character based off fan art from the game New Super Mario Bros. U Deluxe released earlier this year.
She eventually started up a Patreon and now has over 2,000 people willing to give her money every month for access to her Snapchat and "lewd photosets".
On March 1, 2018, PewDiePie uploaded a video titled "I Paid Belle Delphine $0 (she is happy)" in which he plays a video of her dancing on Instagram and thanks her because he can now use her in the thumbnail and get millions of extra views.
I think this meme sums everything up pretty well.