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.
(they also have the ones below)
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.
Or you might find something at:
Hope that helps