You might place a similar comment on lost pets pages like Melanie Pugh's site http://www.pet-detective.com
and other similar sites that cater to and assist lost pets and their owners. And you could put up posters (you can make them cheaply on your computer) and email the local rescue groups in the event they find the cat. Some local pounds will euthenize a cat after just a few days so it is critical her owners find her asap. I would think this cat's family must miss her if she is declawed - much as I don't understand anyone wanting to mutilate a cat like that! You might also email your local newspaper - they often have a list of found pets. Local vets may also know who she is - call around and describe her.
I speak from experience - having found a cat a few yrs ago one Halloween night. I created posters with his picture and emailed the SPCA, local vets, the newspapers and web sites and tracked down the family who "owned" the kitty. I hope you have as much success.
Good luck!! I am so happy you are kind enough to take her in - you are her