The conclusion is a very important part of an essay. You want to leave your reader feeling fully satisfied. The best way to do this is to remind the reader of what you said, and leave the reader with some kind of concluding thought.
First of all, there is no standard format to a conclusion, but I like to follow a pattern that mirrors the introduction.
Part 1: Thesis (restate your thesis, in slightly different words if you like)
Part 2: Review points (review your arguments, hopefully you have three, in one sentence or multiple sentences)
Part 3: Concluding thought (this might be an interesting quote, a question, or some words of wisdom we learned from your essay)
People often relate to the character of Ophelia. Your concluding thought might capitalize on that, relating a lesson we can learn from the treatment of Ophelia in the play.