In The Secret Life of Bees, Lily is a fourteen year-old narrator who frames her story in the first person.  This narration is common to coming-of-age bildungsroman literature, especially Southern civil rights novels (e.g., To Kill a Mockingbird).  After all, Lily's name is taken from the white flower, symbolic of youth and innocence.

Lily moves from innocence to experience as she makes a religious pilgrimage to the Boatright house.  The natural and religious symbolism revealed seems too mature and academic for a young teen, so we must believe that a grown Lily narrates looking back on her formative years.