Here's a good link:
Cat Food 101: What You Need to Know About Feeding Your Cat
The Newman's brand lost me at soy and oats.
I would try and find one that doesn't have grain in it.
Cats are carnivore's, they need meat not grain.
I'm not sure what type of stores you have around you.
Do you have any special pet stores besides Petsmart or Petco?
Here we have Holitisic for Pets or Boneappetite which only carry better quality foods.
I would try to find a specialty store because they usually have better selections and also give away sample bags so you can try the food first.
Are you only wanting to feed dry food?
The wet food is better because it gives them more meat, and more moisture.
Cats are prone to get urinary crystals especially ones who only eat dry food.
Read this:
What causes crystals in cat urine? - Yahoo! Answers
I had to send a cat to rainbow bridge because of these crystals.
Spent $2,500 on surgeries trying to clear it up and this is what started me reading books about pet food. The vet had no idea about food and the vet I go to now said that they study about two weeks of nutrition in school and most of it is sponsored by Aims
The worst thing to do is just leave food out all of the time.
They really need to eat twice a day.
I feed mine in the morning and at night.
I put it down and they eat it up...just like a dog.
I don't let them have people food either.
If you only have the option of a Petsmart type store, the Blue Buffalo brand is decent but there are better brands out there.
Did the vet say if she is overweight?
If so, you may need to get an indoor formula or one that is made for an overweight cat.
I've been feeding mine a raw diet (Rad Cat) for years so I haven't looked at the other type of food for awhile.
The people in the pet store's are sometimes knowledgeable and sometimes not.
I would stay away from Iams, Science Diet and Royal Canin.
Let me know what kind of store's you have to choose from.
I'm glad to help.
Did you give her a name yet?