I surely have no idea. I'm so sorry your lil one is going through this.
If that is what's going on, then please read the following link. It states that you think they are stroke symptoms. Please keep us updated and let us know how she does. I can imagine how scarey this is for you, but if your vet gave an accurate diagnosis then this should not be but a temporary illness.
What is Canine Vestibular Syndrome: Despite Stroke Like Symptoms,The Dog's Health Prognosis May Be Good