I found some links for you that may be helpful if you want to buy cat treats. I think these are like the jerky treats or rawhide for dogs.
You might want to ask your vet about this but I found this statement on the net: "Your cat is not weird if he or she likes rawhide. Their sensitive noses can sense the high protein and fat content" and therefore I would think that buying the compressed rawhide chews for dogs (so they don't choke on chunks!) wouldn't necessarily be a bad thing, as long as she doesn't get too many of them.
http://www.naturalcat.com/store/cust...cat=249&page=1
(they also have the ones below)
http://www.thecatconnection.com/page...CRNCH/TRT-0805
Also, here is a link to some homemade cat treat recipes, you may be able to alter the size of these so your cat has to chew on them more.
http://www.simplypets.com/pet-recipes/Cat/Treat
Or you might find something at:
http://www.recipezaar.com/r/256
Hope that helps