The original AWFW storyline ended with Andrea falling off the Tower of Americas and becoming an angel Even now, I call the story we're in "The Sequel" despite the fact that I never really said "Okay, original story over, onto a new one."
The sequel we have now, involving the Angel/Shadow war didn't exist before The Great Episode 13 Story Shift. In fact, in the early versions, the Angels and Shadows were somewhat working together. The entire sequel was just an exploration of heaven and had a completely different, not-as-benign, and even slightly silly depiction of heaven.
Most of it hinged over the fact that in most theologies, angels have no souls, and Andrea's soul was pretty strong...but also beginning to dissapear as time went on.
A brief outline:
With Andrea dead, her sould is ushered into heaven by Hanna, who offers her a choice of afterlife. Go back to Earht, reincarnate, and forget everything that's happened, or be an angel, helping people along the way. She decides to help people.
She's taken to a school where she is taught from the ground up, never complaining. She is allowed to choose her appearance, and she chooses her 17 year old self, with wings. Hanna tries to dissuade her from the wings, but she feels she's deserved them, and, frankly, she has. That night, Andrea attempts to sleep...much harder with a set of wings.
At school, she trains on how to help descreetly, to guide people down their correct paths, and how to answer prayers. Prayers are handled by the Infinte Secretarial Pool, the host of angels who send messages up to God, who replies via the secretaries. No one ever sees him, and he sees no one.
Her last night before "graduating" she's able to finally sleep comfortably, shrouded by her wings.
She spends the next few hundred years, helping and guiding, using her love for people and humanity to press on. However, as time goes on, the more she helps, the more she feels detatched form the people she's helping. Hanna tells her, this is normal - angels do not have souls, and hers is slipping away. She's deeply troubled when she finds out Hanna still sees her as just another human, the same as she did the first day they met, the same as she sees all humans.
Unable to bear the thought of losing her love for humanity, she decides to reincarnate and return to earth with no memory of the last several hundreed years. The only angel to do so.