I really think a second vet opinion is in order, and that more testing needs to be done. At the very least, she needs follow-up blood work inside of a month.
A low white blood cell count CAN be indicative of an infection, thus the conflicting information. Apart from distemper or infection, it can be indicative of FIP, bone marrow cancer, and an autoimmune disease. It seems to me that further tests are necessary, and if you can locate a feline specialist in your area, that would be the best idea.
The not eating is of GREAT concern. When our Tuxedo developed an autoimmune disease, not eating was one of the later stages of the development of the disease. We'd put the food bowl in front of him, and he'd just stand there. Our (second opinion) vet told us to feed him ANYTHING we could get hiim to eat. Shrimp was what we could get him to eat. Tuna, Shrimp - it doesn't matter if it's not the best food for kitty, she MUST eat - and if she won't eat, at some point you're going to have to consider force-feeding her.
Before you get to that point, try baby food. Beechnut or Gerber - the meat baby foods. Try Chicken first. Then Beef. Then Veal. Cats have trouble digesting ham, but if she'll eat it, feed it to her. I'd also consider boiling a chicken (with nothing but water and chicken in it), and feeding her both the cool broth and small bits of chicken.
If it is FIP, there are things you can do to make her time with you more comfortable.
The disease may have been dormant in her since you've had her - it may not even be an issue of how she was exposed to it. Could have been to another cat while at a shelter, or a problem at the breeder's (this has happened) - or she was born with it from a mother carrying the disease.
We almost lost our kitty twice to the autoimmune disease that affected him, and our first vet told his his symptoms were nothing to worry about. If we hadn't gotten a second opinion, he'd be dead. Please see another vet!