If you're going to do some research into it, might I suggest trying to find a cat only vet? They seem to be well versed and take more care into the, shall we say, "special quirks" that so many kitties have. And especially if this is stress/behavioral, they will likely have much more information on the best ways to improve her well being. And same goes for if she has a particular allergy. So many don't have a lot of training in cat nutrition, but I would assume a cat only vet would have the additional knowledge.
That's not to say that a vet who deals with all animals will not be a good choice, my vet is a multi-species vet hospital. But they take it upon themselves to keep up with additional training and such.
And feel free to keep us updated on her results, we do have a lot of collective experience to help you along the way. But for me, I can't really offer you much right now, if I don't know what you're dealing with.
Best of luck to you and your kitty!!!