Will Justin Bieber be my son-in-law?

My daughter loves Justin Bieber.  The other day she told me she wants to marry him and today she called him, "my man."  When shopping for Valentines last weekend, she choose a set with his picture on them.  When she pulled out an included poster, she gasped because it had his autograph on it.  All of this seems pretty typical, right?  The only concerning detail here is that she's six-years-old - and doesn't have a CD of his.  We've never seen him on television except for commercials for his upcoming movie.  Today she asked why his voice used to be high and now it's lower.  So no only is he stealing the heart of my baby, but now forcing conversations about puberty.  Where did this all come from?  And how do I redirect her back to playing Mommy to her dolls?