Good morning, I just have a few questions so I can assist you
Whas she checked for worms or internal parasites.
Was she tested for feline leukema or feline aids.
ok, yes she needs to go back to the vet, the fact that she is still not eating means she is not ok.
I would request my vet get alittle more aggressive in finding the problem and not continuing to say she is fine.
It is very dangerous for a cat to go more then 2 days with out eating, after that their organs (Kidney and Liver)begin to show signs if shut down.
It is also very common for cats who have been force fed to acquire a food aversion so that should be the last resort.
Try appyling a small amount of pancake or kyro syrup to her gums to bring her blood gluclose up which I am positive is low due to lack of eating. Low blood sugar will cause her to become more lethargic and can be fatal
Even though your breeder says they dewormed her I would still request a stool sample to check not only for worms but other intestional parasites.
Ciproheptadine is an amazing drug used to stimulate a cats appetite so I would ask your vet about that.Some vets also use valium as an appetite stimulant.
I do not like to disagree with a vet but your baby is very obviously not fine so you must be her advocate and demand that they find the cause.
I will be online all day please keep me posted on her condition
Technician
Practicing Veterinary Technician for 23 years. Veterinary Practice Owner, Technician Trainer