Robbie Ray was a singer before his wife died, then he gave up his career. His two children were born before that when he was still a singer. So, wouldn't the media have found out the names of his two children? He couldn't have called Miley Hannah Montana because she wasn't always Hannah. It says so in the episode where Miley has a dream about her mom. She says something along the lines of "Your friends loved you before you were Hannah Montana and they'll love you long after." It would have been well known that Robbie had only two children and in many cases Robbie Ray is called by his name and it has been said that Hannah is his daughter. Everybody knows how old Hannah is and I think it was stated when she was on a talk show with Mikayla. How many 15 year old girls can a guy have? So since Miley is his only daughter, wouldn't Miley have to be Hannah?