Seconding the idea of a tick panel before you pursue imaging at a neurologist- particularly if you acquired her as an older pup or adult dog- exposure could have happened before you got her. I would ask for the send out panel, not the snap test (which only tests for 4 TBDs). AmStaffs and APBTs can also have a disease called cerebellar ataxia, which causes lack of balance/coordination, but not paralysis or limping- just throwing that out there in case it sounds like it could fit.
I have known of a few pit bulls/pit mixes who have had disc issues/IVDD symptoms, which I've thought is strange, and hope isn't becoming a more prevalent issue in the breed. Maybe because of their bulldog heritage? But I digress. I have had a dog with IVDD/pinched nerve, and her issues resolved with medication both times, luckily. Her xrays were fairly normal and my vet recommended treating based on her breed and symptoms, as often MRI or myelogram is needed to actually visualize and diagnose disc problems and it wasn't an option due to cost.
If you are concerned because of the dosages of the medication that are being prescribed, keep in mind that animal dosages can vary widely from human dosages, so what seems like a "huge" dose may not actually be for an animal. You can certainly ask the vet how they calculate the dose and check the math yourself if you are concerned.
If your girl does have a disc issue, it is imperative that you restrict her activity to prevent further injury and hopefully allow the injury to heal or stabilize. Usually strict crate rest and short leash walks are recommended for several weeks (at least), with a slow increase back to normal activity. It is unpleasant, but only temporary, vs not doing the restriction and having the issue worsen or become permanent.
Hope you figure out the problem and are able to find a solution. She's very cute