Facebook is a social networking site which is meant to help friends and co-workers stay in touch with one another. However, the site also has a privacy setting for a profile which sets it to private, meaning that casual browsers can't see the information listed in a private profile unless the owner of that profile adds the viewer as a friend. However, that doesn't mean that it makes the holder of that private profile any harder to find.
Go to facebook.com. Log in to your own profile so that you can browse the site under your own name and information.
Click the section on the page labelled "find friends." Type in the name of the person for whom you're looking in the space provided and press "Search."
Go down the list of people that the search offers until you find the person for whom you're looking. If her profile is set to private, meaning that you can't read her information, it can be hard to tell if it's the person for whom you're looking. Send the person a message and ask her if she is that person. When you send a message to a person on Facebook, you're given temporary access to her page once she replies, so check the person's page if she writes you back.