I can only recommend a stay at Mary's house. It's a cozy, clean and inviting place, the room is indeed small, but absolutely sufficient to provide "a home away from home" for a few days and especially when you're probably out to roam the streets and sights of beautiful Edinburgh for most of the day anyway.

Mary made me feel welcome and opened her home to me like a good friend. She happily provided a quick overview of what sights to see and where to go and we had some nice chats about my first impressions of the city and this and that.

The location is within walking distance of the old town city centre with most of the sights, but you can also take the short trip by bus if you're tired of the hills. ;) The house is in a nicely quiet residential area, so you can really relax after a full day and the Botanic Garden plus a few parks and walking trails aren't far away either if you want to take a break.