Avalanna Routh 'Mrs. Bieber:' Justin Bieber responds after biggest fan loses battle to brain cancer

NEW YORK, N.Y. -- Avalanna Routh, the 6-year-old whose love for Justin Bieber earned her the nickname "Mrs. Bieber," lost her battle with brain cancer Wednesday, according to CNN.

Her family posted on her Twitter account : "Our darling Avalanna went to Heaven this morning. Oh Avalanna, the brightest star - you took our hearts with you, our greatest Love." Twitter account , CNN reported.

Routh was battling a rare form of brain cancer. But this past Valentine's Day, Justin Bieber brightened her life.

Bieber flew the little girl and her family to New York and spent the day with her.

Bieber later said it was one of the best experiences of his life and that little Avalanna was "awesome."

When Bieber learned of Routh's death, he tweeted , "just got the worst news ever. one of the greatest spirits i have ever known is gone. please pray for her family and for her. RIP Avalanna. i love you."