Gosh I hope she comes back. You may want to check www.Petfinder.org just in case someone found her. Also call your local shelters and the spca to see if they have her too. They may have found her and are looking for her owners.
Thank you anyways though, I have been checking websites like that, our Sacramento SPCA doesn't usually take in lost cats, only cats that are given up, but another one does and I looked on their website. It is just that there are a ton of black and white tuxedo kitties!