After earning law degrees in both Germany and France, Gaby followed her passion for the arts to the Tate Gallery in London. There she started as a docent, then became a lecturer on both British and international contemporary art.

After coming to California with her husband, Nicky Hahn, she continued her commitment to the arts, lecturing on topics such as British art, Californian art, impressionism and sculpture. She served as a trustee for the Monterey Museum of Art, the Monterey Symphony, and the Monterey Institute of International Studies. She also founded an art appreciation unit at the Washington Union School District to introduce art to children in Salinas.

In 1997, the Hahn family acquired a 50,000-acre farm in Laikipia, Kenya where they created a wild animal conservancy. Inspired by the profound beauty of the people, animals and landscape, Gaby has made the farm the primary topic for her art.