The thing is, I can't afford to spend much money on her. If it comes down to having to spend a lot of money on her, and then on my other kitties if she infects them, my only option unless god comes down from heaven and hands me a duffel bag of cash OR if I go to doing highly illegal, highly dangerous criminal activities, is to take my kitty out, tell her I love her, pet her and then put her down myself.
Edit: when I called them, they said it "is just some respiratory infection.. bring her in for the doc to look at her, it'll cost 26 dollars plus medication".
I'll bet you can get her well on your own. You should confine her in a single room while she recuperates to prevent her from spreading the cough. Set up a warm steam vaporizer in the room and that will make the mucous liquid so she can cough it out and prevent pneumonia.
When animals are sick they don't eat, so you have to find stuff that's irresistable. Human baby food is some of the best things for sick animals because it is loaded with vitamins and minerals (and calories) so babies will gain weight and grow. Find some flavors she will like. Maybe chicken or beef? You could also try canned tuna. Even ice cream if she likes it. Most important thing is to keep her fed and hydrated. I'll bet she can beat this thing.
EDITED TO ADD:
You can use children's medicine like cough syrup with expectorant to help her get out the infection. Be sure to dose it for her body weight.