I hope your vet can figure out what is wrong with her.
I have Czarina insured with the ASPCA insurance and I used to insure the gang with a company called Pet Care. I know some people have just a separate credit card and only use it for their pets. I have one that has low credit on it, but I use it (when the balance is low) for any vet visits. I'd like to do that with two other cards I am trying to pay down. To just have them for vet visits.
The only problem with getting them insurance is you still have to pay up front for anything like an illness. Then you fill out a claim form and you get back whatever your policy gives you.