Character Analysis
Ghostess With The Mostess
Even though she's definitely one of the two villains of this story (from a conventional point of view, that is), we don't really know anything about Miss Jessel.
We know some of her backstory—she came from a good family (she was, after all, a "lady"), and worked at Bly as the children's governess before our narrator arrived on the scene. While at Bly, she had an illicit and possibly quite racy relationship with Peter Quint; this relationship was further complicated by their class difference.
However, beyond this, we really don't know anything except her physical appearance—and even that's a little sketchy:
"Another person – this time; but a figure of quite as unmistakable horror and evil: a woman in black, pale and dreadful – with such an air also, and such a face! – on the other side of the lake. I was there with the child – quiet for the hour; and in the midst of it she came." (7.3)
All we know is that she—or at least her ghostly form—likes to wear black, often looks weighed down by something (by misery or by evil), and is exceptionally beautiful.
Oh yeah, and she's very, very creepy…but that could just be the whole "ghost" thing.
Miss Jessel Timeline