I ran all over Esteldin before finding Viola, as she doesn't show up with a 'ring' on the map.
The coordinates of the building door are 9.7S, 41.6W.
Be sure to buy your carving recipes, and any others that you don't have. There is some serious mark up between this forsaken place and the AH.
Hope this saves you some time.
Felseth - Lord of Streams
Gladden Hunter 23