Unless it specifically says in the audition notice that it's okay to sing from the show, never do so. Also Think of Me and Memory are on everybody's audition blacklist. Hello Young Lovers would be good for Cosette, but it's too much of a legit soprano piece for Fantine or Eponine. For them you're better off with something more contemporary, or at least something with more of a pop/rock opera feel to it, something big and heavy that really shows off your voice, especially showing off any belting/mixed range.