She served on an Allied commission to observe the Greek elections of 1946, worked for the US Information Service, and was subsequently the cultural attaché of the US embassy in Athens.

Her publications included some of the earliest archaeological research into Ottoman Greece, as well as photography of archaic kore sculptures, Byzantine architecture and artifacts from the Aegean Bronze Age.

She was considered among the foremost photographers of ancient Greek antiquities, and her work has been cited as a major influence on the scholarship and popular reception of classical Greece.

[2] Her father, a newspaper publisher, died of pneumonia soon afterwards;[4] her Scottish mother, Mary Kate Frantz, moved the family to Edinburgh.

[7] Among her teachers at Smith was the art historian Clarence Kennedy, whose use of photography to record ancient and renaissance sculpture, aiming to minimize personal style in favor of documentary accuracy, influenced Frantz's later work.

[3] During this time, she made her first visit to Greece,[9] on a short trip organized by the Academy's director, Gorham P. Stevens, and his Greek wife, Annette Notaras.

[21] During the 1930s, she worked largely on Byzantine painting, and made a study of the frescoes of several churches – demolished shortly afterwards – which was illustrated by the artist and draughtsman Piet de Jong.

[24][a] Just before the Second World War, Frantz photographed in two days more than six hundred tablets inscribed in Linear B from the Mycenaean site of Pylos, brought to Athens by their excavator, Carl Blegen, for safekeeping in the Bank of Greece.

[26] A set of prints of the photographs were delivered in 1940 to the University of Cincinnati, where Blegen worked, and were used by Emmett L. Bennett to make the first transcription and edition of the tablets, which he published in 1951.

[28] Several archaeologists of the ASCSA, led by Rodney Young and Benjamin Meritt, founded the American School Committee for Aid to Greece, which purchased ambulances to send to Greek forces.

Frantz joined the committee alongside T. Leslie Shear, who had worked with her on the Agora excavations, Talcott, Edward Capps, George Elderkin, Hetty Goldman and Oscar Broneer.

[31] Frantz and Young were among several archaeologists, including the Americans Blegen, Meritt, and Shear and the British Alan Wace, to serve in Allied intelligence services in Greece.

[32] She was recommended to the OSS by Meritt, then head of the Greek section of the organization's Foreign Nationalities Branch (FNB), for whom she had worked part-time as an indexer at the Institute for Advanced Study in Princeton.

Frantz's official title was Junior Social Science Analyst; her work primarily focused on interviewing political exiles from German-occupied Europe.

[37] In 1944, James Murphy, the head of the OSS's X-2 Counter Espionage Branch, unsuccessfully attempted to recruit Frantz for counterintelligence work.

[40] Frantz arrived in Athens on January 8, where she and Blegen, based at the latter's home at 9 Ploutarchou Street, created a training course in Greek history, politics and culture for the other American members of the AMFOGE.

[45] In this capacity, she established the Fulbright Program in Greece, which sent ten scholars and eight senior research fellows to the ASCSA in 1949,[46] and played an important role in restoring the Athens Symphony Orchestra.

[47] Throughout the 1950s, she delivered lectures in Byzantine Greece – at the time, an area rarely taught at US universities or in the ASCSA's courses – for visiting students and scholars.

[48] Between 1954 and 1957,[49] Frantz and the archaeologist John Travlos supervised the restoration of the Church of the Holy Apostles, constructed around 1100 and the only surviving Byzantine building in the Agora.

[51] Around 1958, she and the art historian Rhys Carpenter climbed Mount Pentelicus, guided by Homer Thompson, the director of the Agora excavations, to photograph an unfinished marble colossal statue near the summit.

[66] In their history of women in the Agora excavations, Susan I. Rotroff and Robert D. Lamberton described Frantz as being ahead of her time in her advocacy of a diachronic approach to the project, as opposed to the singular focus on the classical period then dominant in Greek archaeology.

[67] The archaeologist Joanita Vroom has listed Frantz, alongside her ASCSA colleague Frederick Waagé, as one of "the first pioneers" of Ottoman archaeology in Greece.

[72] Most of these were hitherto unpublished; writing in The Princeton University Library Chronicle, Patricia H. Marks called the Frantz archive "an archaeologist's dream".