Appropriately, Teenager is comprised entirely of material Jane Siberry wrote as a teen and recorded as an adult.
While the songs aren't quite as accomplished as her later work, it's nevertheless surprisingly engaging -- it's quite melodic, and the songs often have a bright, innocent quality which is quite refreshing in light of the somberness of much of her later work.
Still, these are subtle differences that only the most devoted fans will be able to hear, and those are the fans who will cherish Teenager the most.