If the kitty won’t eat dry or wet food, you can try adding some water to the wet food and putting it into a syringe and feeding her that way directly into her mouth. You can slowly administer the food into her mouth almost like using a baby bottle. Do not overdo this, only feed as much as she can handle.
Milk Thistle and Turmeric are helpful to be given at this time, as they will help strengthen her immune system and help detoxify the body.
Felimm is another supplement that may help your kitty because it helps fight against Feline Leukemia, and Feline Immunodeficiency Virus. The combined herbs help fight infections as well as upper respiratory tract infections. It also encourages detoxification of the lymphatic system, while stimulating the appetite. This would help stimulate her appetite once she's started controling the issue at hand.
We also need to consider seeing a veterinarian. Is she lethargic? Is there another underlying issue there? Getting seen by a veterinarian to rule out any underlying issues that we may not know about is also important. They could also give her IV fluids that would help in the meantime since the kitty is not eating. The fluids would help with any nutrient deficiency and would also hydrate her if she is not drinking water.