Sounds like you’re on the right track. I would also recommend a good food (I use Wysong). That being said, my guess is that the culprit is a leftover parasite infection. De-wormers are fairly specific to the particular worm type. The Strongid only works for round worms and hook worms. Anything else would be unaffected. It’s also possible she has a non-worm parasite, such as giardia, or a bacterial infection. I would recommend another fecal examination if the second round of Strongid doesn’t work.
Also,one thing that might help with any vet bills is some vets take a credit card called Care Credit. It can also be used for human doctor, dentist, etc. visits. Most vets and doctors have a promotional period during which there’s no interest if paid off in full. It can range from 3 months to a year. It might be worth checking into.