It’s Miley Cyrus’ Little Sister, Noah!
That youngin' you saw before is Noah Cyrus, little sister to 'Party in the U.S.A.' hit maker/'Hannah Montana' starlet Miley Cyrus! Miley actually calls her Noie, proving that nicknames run in the Cyrus family.
Noah totally looks up to her big sister Miley, but these two girls are not the only kids in the Cyrus clan. They have half-siblings Trace, Brandi and Christopher (who was raised by his mother and not with his father, Billy Ray), and then there's Braison -- Miley and Noah's full-blooded brother.
Noah is only 12, but she's already voiced the main character in the U.S. version of the anime flick 'Ponyo,' where she also showed off her singing chops, and has starred on shows like 'Doc' and guest starred on Miley's show 'Hannah Montana.' It's nice to see that Miley gives her sis time to shine in the spotlight. Now only if she can get One Direction to perform at Noah's next birthday bash...
Watch Miley Cyrus Bring Noah Cyrus Up on Stage for 'Hoedown Throwdown'