No Ordinary Girl (also known as Ordinary Girl, and An Ordinary Girl) is the main, and current title song of H2O: Just Add Water. It is performed by Ellie Henderson throughout season 1, and Kate Alexa throughout season 2. In season 3 Indiana Evans as Bella Hartley sings it, and the song is in a lower pitch. (G to F) It was written by Shelley Rosenberg in real life, and by Bella Hartley in the show.