Check into Care Credit. I ended up getting this to use for Bayleigh's medical treatments. It can also be used at various doctor, dentist and other medical offices.
Just a piece of advice if you vet doesn’t find anything it might be worth seeing an ortho specialist sooner rather than later. My foster was examined & x-rayed by a general practice vet and we were told it was nothing (just a sprain or pulled muscle). We wasted over a month resting him & using painkillers. Finally I took him to an ortho vet who took one look at him and knew both his knees were bad. I have since gotten two more opinions from surgeons and they all said the same thing. With ortho injuries its worth seeking a specialist. Good luck & I hope she is feeling better soon!