"It is with a heavy heart that we share with all of you that Talia has earned her wings at 11:22am," her family wrote on Castellano's Facebook page. "We will miss you more than you will ever know baby girl."
Castellano was diagnosed with cancer when she was just 7 years old. After she began posting makeup tutorials on her YouTube channel, she gained a following of more than 845,000 subscribers. In 2012, Castellano appeared on Ellen and got the surprise of a lifetime when she was named an honorary CoverGirl. DeGeneres also sent her to the iHeartRadio music festival where she interviewed some of Hollywood's biggest celebrities.
"It's a sad day at The Ellen DeGeneres show, read a post on the show's Facebook page on Tuesday. "This morning, we lost a friend. Talia Joy Castellano was an inspiring young makeup artist with a lot of talent and a lot of heart. She inspired everyone at the show, and many, many more. Our hearts are with her family. We love you, Talia."