Hi, and welcome to YorkieTalk! That's great that you're asking about the food. Purina is not a high quality food in my opinion...And Mighty Dog and Cesar's are not either.
There are many reasonably priced high premium dog foods that you could buy instead, or better yet, you could try homecooking for her.
www.dogfoodanalysis.com is a good starting point. Try to find a 4 or 5 star food. Look up their websites online and see if they have any stores that sell those foods near you.
There's a sticky in the Health & Diet section that has a bunch of recipes for cooking for your dog too. An excellent book to get started with is Dr. Pitcairn's Complete Guide to Health, but there are others as well...