She had the highest grade point average and graduated with her Civil Engineering degree in 1947, the first woman in all of Central America to earn a mathematics degree and graduate as an engineer from the Universidad de San Carlos de Guatemala.

[1][9] While she was working on her engineering degree, Fernández-Hall taught at Colegio Belga and the Instituto Normal Central para Señoritas Belén.

When she moved to Brazil to continue her studies, she joined the foreign service and served as Cultural Attache for Guatemala.

After graduation, she had a lengthy diplomatic career, representing Guatemala in Greece, Israel and Costa Rica.

[11] While serving as ambassador in 1959, she helped musician Jorge Sarmientos launch his international career,[12] and in 1960 she met Golda Meir.