The Governess is the only character we can really sink our teeth into in this story, and boy, is it worth it. She's a truly fascinating character; we're never quite sure how trustworthy she is as a narrator, but at least she never fails to keep us on our toes.
As for the facts, they are relatively few and far between: we know that she's only twenty years old, and that she's the daughter of a poor country parson. She's clearly something of a romantic, at least at the beginning, and this inclination contributes to her acceptance of the job at Bly. Though she only meets her employer twice, she's sufficiently swept off her feet, and spends the rest of the story secretly in love (or something approximating it) with him.
Now that we've got the easy stuff out of the way, it's time to tackle the more complicated elements of the Governess's personality. There are traditionally two ways of viewing her character – as either a sane heroine or a insane anti-heroine. Both sides have passionate adherents; if you ever want to pick a nasty fight in a room full of English majors, bring up The Turn of the Screw. Let's take a look at both of these cases – we leave the final verdict up to all of you.
How could you doubt her? The Governess is totally sane.
The classic reading of this story is that we assume that our heroine to be in full possession of her mental faculties (that is, she's not crazy), and that all of these supernatural things actually take place in the real world. This view of the Governess places her in the role of the traditional heroine, and assumes that she is really acting for the good of the children; it also assumes that the children are in fact in cahoots with the ghostly visitors, and that both Flora and Miles are little deceivers.
If we are to look at things this way, then we see the Governess as a strong-willed, intelligent, and noble young woman, who ultimately ends up a victim of Quint and Jessel, as do the two children.
Don't trust her! The Governess is a madwoman.
The most popular alternate reading of the character is that the Governess is 100% certifiably insane, and that the supernatural activity is all a manifestation of her tormented, repressed mental state. This psychoanalytic perspective was first proposed by the influential literary critic Edmund Wilson, in a 1938 essay entitled "The Ambiguity of Henry James." In the essay, Wilson carefully lays out several instances in which he sees signs of Freudian symbolism in the story; the Governess stands out as a neurotic, sexually repressed woman, whose hidden desires drive her mad. Wilson's essay generated a whole lot of conversation around the story, which has always been one of James's most oft-discussed works.The Governess Timeline