Filed under: Teens and tweens, Celeb kids, Life and styleI knew Miley Cyrus' career was going pretty well, but this is unbelievable. At the tender age of fifteen, Cyrus has found huge success as a singer, actress and amateur model. Everybody knows her name and the cash is rolling in at a steady pace. In fact, according to People, the girl will soon be a billionaire!She's already the richest kid in the world and her future looks even greener. She made a whopping