Sarah's appartement is very nice, located in a private court hence very safe. The appartement is approximately 25 minutes walk from the city center, there are buses close to the appartement. And Uber is active in Edimburgh. It has two rooms, a nice bathroom, nicely equipped kitchen and we were welcome with a great basket of products (biscuits, bread, milk, jam...).
We haven't met Sarah, but her communication was great as well.