The real Harriet is probably a psychopath. She takes meticulous and consistently negative portrayals of everyone she knows (or finds): her parents, classmates, and random strangers in Manhattan whom she spies on through windows. (In one case, she goes so far as to break into a woman's house and go up the elevator to watch the woman in bed). Her life plan is to become the most famous writer in the world and to know EVERYTHING EVERYTHING EVERYTHING (she also has a fondness for all caps). The obvious problem is that she lacks an ounce of empathy for the people in her way, and she takes delight in crushing them. The only person with the ability to have a good influence on her is the no-nonsense nurse Ole Golly, who gets married and leaves Harriet about mid-way through the book. The rest of the book is about Harriet coping with this loss in increasingly destructive ways before finally learning the basics of empathy. The book is a complex, subtle look at the different ways of knowing, and it shares a lovely secret: that you can know all the scientific, surface details of a person without knowing them at all.
I can't expect the movie to match the complexity of the book. What I can expect is for Harriet to still be Harriet. Here is Harriet M. Welch sporting her "spy gear," the belt equipped with flashlight, canteen and other supplies which she always wears on her spy route:
And here is the movie version of Harriet with her notebook:
There is more to be said, but in the interest of shortening the blog post....