It's great that Peg is improving. We've had two of our dogs as seniors develop vestibular disease. Both recovered within a few days to a week (at least enough to be able to walk and handle elimination without aid). Megan learned to lean against the wall when walking up and down stairs to aid in movement.
I've seen scores of dogs (and cats) develop this syndrome. Many owners think their dog has had a stroke and are prepared to euthanize them, only to find out that this is a temporary condition that usually improves with minimal supportive care.
Doug, DVM