We are terribly saddened by the death of 13-year-old Talia Joy Castellano yesterday on July 16. A popular and positive YouTube beauty guru and CoverGirl, Castellano's beautiful smile could light up a room and our computer screens with her vibrant ethusiasm. We pay tribute to her with our slideshow.

The gorg girl, who lost a seven-year battle to cancer, loved all things beauty. She also had an amazing outlook on life that would put any optimist to shame. Hearing her speak, we never knew that she struggled with a form of nerve cancer called "neuroblastoma."

Instead, Talia was an online beauty source, gaining adoring fans all over Twitter, Facebook and the 'Tube. Castellano even appeared on "The Ellen Degeneres show" and became an honorary CoverGirl. This girl definitely rocked.

Ellen was so moved by her strength like us. "This year, I met a very special girl, and today we lost her," the talk show host tweeted. "Sending my heart to Talia's family. I'm so sad."

"Having cancer has been a gift yet a horrible, horrible, terrifying thing," the special girl said in one of her most-watched viral vids. "But, I've gotten so many benefits from it...Having a YouTube channel and having people look up to me and explaining to you guys how I love and adore makeup, using it as my wig and having so much self-confidence to go out to the grocery store without a wig...it's just amazing."

CoverGirl released a statement on how fab and inspirational Talia was to so many young girls everywhere. She embodied the true meaning of beauty, they said.

Our hearts and thoughts go out to Talia's family, friends and fans. Let us know how Talia touched your life in the comments below.