Answer

Hello,

Usually, with symptoms as you describe, external parasites like fleas or mites, would be considered, first. Even though she's not scratching/itchy, these can't be definitely ruled out until she's tested.

http://www.sniksnak.com/cathealth/allergies.html
http://www.sniksnak.com/cathealth/flea-allergy.html

A form of alopecia, like feline psychogenic alopecia, an obsessive-compulsive condition, may be the cause of the hairloss on her sides:

http://www.petplace.com/cats/psychogenic-alopecia-in-cats/page1.aspx

If your vet already concluded that she seemed to be mildly allergic to something, perhaps the chicken in her diet, that you have since eliminated, it's also possible that she's allergic to the present protein source (meat) in her current food. Some cats develop these allergies and some food manufacturers like Natural Balance and Royal Canin carry a line of 'limited ingredients' foods, with alternate protein sources and carbohydrate ingredients.

http://www.naturalbalanceinc.com/catformulas/allergy.html

Contact dermatitis and allergies to airborne irritants, are also possible, if your cat has sensitivities, and if her current food contains any corn, wheat, soy, gluten, dairy products and/or artificial additives/preservatives, these are also common allergens.

It would be a good idea for Grace to have a routine blood test done, just to rule out any underlying medical conditions, and an analysis of her skin/fur from these affected areas would also be recommended (a skin scraping is painless).

Have you considered any sensitivity to her current kitty litter? Try changing to a different and/or unscented brand and see if this makes a difference.

Once some tests are conducted in person, by the vet, hopefully, you'll receive a definite 0diagnosis and then the most appropriate treatment will be prescribed, if necessary.

I hope all will be well with Grace!

Cher