Ingenue

[Sarah]

A [stock character] in [opera], [theater], and [literature]. She is a girl or young woman who is [endearing]ly [wholesome] and [innocent]. Very similar to the [girl next door].
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.

[Becky]

A female character in drama or literature. She is a sweet, pretty, if somewhat naive, young woman. To our modern eyes, shes often seen as this [meek] [little mouse].
The ingenue is played by a light [soprano] in opera or musicals.