Hey Jay,
Sorry to hear about your ill Kitty. Tracy and I have had 4 cats that have each lived happy lives until about 17 years of age. The best advice we can give you is to take your cat to your Vet for regular checkups. Blood and other tests will let them know what kind of diet is best for your kitty. Raw or Yummy food might make her happy initially but may upset her stomach later or cause other problems. The only way to know what diet is best is to have proper medical exams. It will cost you some, but it will be worth it.
Good luck!
ps: Here's a pic of our little terror:
