Can you tell me all of her symptoms and what has improved?
Did they run blood work on her?
What she has is vestibular disease. This is a common condition that can happen in older dogs. Causes of vestibular disease include inflammation of the vestibular system, ear infections, organic disease, brain tumor or toxic ingestion. They are treating it now as an inflammatory condition. It can take dogs up to 3-4 weeks before they are completely improved though a head tilt may remain. I was curious about a thyroid issue as this is seen also in dogs with hypothyroidism so if a thyroid level was not checked then I would request this be done. Also, start working on keeping her protein levels down in the food and increasing her fluid intake. Ask your vet about starting her on benazapril to decrease blood pressure which usually accompanies renal disease.
With this disease there is a lot of wait and see what happens going on. This is normal. She is improving so this is a good sign for her. Keep up what you are doing.
Here is a link that can assist you:
Please let me know if further assistance is needed.