In the 70s, Efthalia studied art history at the Courtauld Institute in London, specializing in Byzantine art. With her supervisor and mentor, the professor of Byzantine Art of the Metsovian Polytechnic Univeristy of Athens, Doula Mourikis, she prepared her doctoral thesis in English on the subject of the frescoes of the 13th c. Panagia Olympiotissa in Elasson, which was published by the Canadian Archaeological Institute of Athens in 1992.

Thereafter she devoted her time to attending conferences on Byzantine art and culture at universities such as Princeton and other institutions, giving lectures, and writing articles. In 2007 her second book entitled  “Images from the Byzantine Periphery: Studies in iconography and Style” was published. It contains nine of Efthalia’s essays on such subjects as “Monumental Painting in Cyprus during the Venetian Period,” “Une icône historiée de Saint Georges du 13ème siècle au Monastère de Sainte Catherine du Mont Sinai,” etc.

Efthalia and her mother founded in 1968 the Patmos Trust of Cultural Heritage whose purpose is the protection and exhibition of the important and multifaceted cultural heritage of Patmos as well as its precious architectural beauty. In 1971 as President of the Patmos Trust, Ethalia purchased with her own funds and supplemented by contributions of her like-minded visionaries "Stavrakas Mansion" and donated it to the trust.  This historic mansion lies adjacent to the entrance of the monastery of St. John the Theologian and has since then been an importanrt center of cultural events and the artistic promotion of Patmos.

Her mother was known for her 30-yr tenure as president of the "The Philodasiki Union of Athens" - the oldest Greek environmental organisation through which she succeeded in having the 600 acre forest of Ymitos Mountain in Athens declared as a Specially Protected Area (SPA) and completing the reforestation of Kaisariani. The reforestation of Perdikari, the forest between Skala and Chora in Patmos, also came to realisation under her own initiative but it would not have been possible without the invaluable volunteer aid of the Patmias Ecclesiastical School of Patmos, whose students planted each seed with immense appreciation and love.

The Patmos Trust of Cultural Heritage, which owes its personality and activity to the long-term presidency of Ethalia, continues its work drawing inspiration and strength from her vision of Patmos.