Some essay help, please!

I'm a first-year Nursing student in university. I have my very first essay due on Friday for my English class (Intro to Prose Fiction). Here is the main idea I'm supposed to focus on:

"The main character of a story most often experiences a change in attitude or awareness during the course of the story. In a short essay of approximately 3 typed pages, discuss the major changes that take place in the main character of "The Story of an Hour."

I don't have a problem coming up with ideas, I just can't get them onto paper (er...screen?). In the story, Mrs. Mallard finds out her husband has died. She reacts in grief at first but then looks out an open window and realizes she has a future now and an escape from the repression of marriage (or so she thinks). She becomes very happy and joyous. There are a lot more details, but that's the main idea. Now, here's my problem: I feel that I should detail how she was before the change, state the point of change, and then detail how she was after that point. I just don't know how to start this thing and in what order to go! In the introduction, I'll obviously state that Mrs. Mallard undergoes a change, but should I state the changes at that point? Or should I say (in the introduction) at what point this change occurs? Or should I say how she was before the change? This probably makes no sense the way I'm telling it, but I'm just at a loss here. Basically, in which order should I write about the changes in attitude? I'm not sure how to transition from talking about how she was before to after though. Arggh, I'm just frustrated! I hope someone can make sense of this and help me out. I'd really like to work on this but I just can't organize my ideas in a way that sounds good.

Thanks!

Chantelle