She is generally portrayed as sweet, gentle, virtuous, beautiful, demure, with the wide-eyed innocence of a child and she is very often naive. She is often the victim of the libertine, whom she may have mistaken for the hero. Often she still lives with her parents, owing to her youth and naivete.
She is usually the foil for the dangerously seductive femme fatale.
She is often involved in a romantic subplot, usually with the boy next door and the romance is typically innocent and chaste.
The ingenue is typically played by a lyric soprano in opera and musicals.
Joanna in Sweeney Todd
Dorothy in the Wizard of Oz
Giselle in Enchanted
Cosette in Les Miserables
Sandy in Grease
Maria in West Side Story
Christine in Phantom of the Opera
Ophelia in Hamlet
Juliet in Romeo and Juliet
Ariel in The Little Mermaid
Belle in Beauty and the Beast
Penny in Dr Horrible's Sing-Along Blog
Mimi in La Boheme
Tatiana in Eugene Onegin