You may want to try to warm the wet food you are offering?
As you have learned, if the cat/kitten can't smell the food they won't eat. The idea is to do anything you can to get them to be able to smell it. Like warming it and or offering something really smelly like the fish/salmon varieties of wet food.
You may also want to try to offer food on your fingertips/hand-feed the wet food or raise the food bowl. It may help her breath better when head is upright, may be more apt to eat with head in more upright position.
Sometimes I find a bit of liquid vitamin can stimulate appetite.
Vicks can help open breathing - put a dab on a paper towel and in the kennel and or smear it on a cloth handkerchief around the neck. I have also put dab directly under nose using cotton swab. In extreme cases I have used afrin nose spray to open the nose - be sure to work with your vet if it comes to using something like that.
Any cat/kitten should not go for very long without eating - it can start an irreversible downward spiral. If the simple things like hand feeding, elevating food bowl, warming the food or offering smelly food, Vicks, etc are not working you will need to get to vet again. May need subcutaneous fluids, and or b-12 injection to boost ability to overcome lack of food.
Also may want to opt for antibiotic injection instead of oral antibiotics. I have found that if the kitten can't smell they usually have a hard time swallowing and spit out most of the liquid antibiotic (amoxi). :(
I'm not a vet. I have fostered cats/kittens for five years now without much support from my shelter and had to learn medical and home remedies on my own, with the help of my vet and his staff. There are other home remedies we have used successfully but I wont mention here for fear of starting an argument. Hopefully just doing some of the basics will help get that kitten eating again soon. <3
All the best.
#PetHealthandNutrition