Dr. Poh Siew Aing married Ambassador-at-large Tommy Koh in 1967 and moved to the United States where Koh served as Singapore’s permanent Representative to the United Nations and Singapore's fourth Ambassador to the United States between 1968 and 1990. As an ambassador’s wife, Poh was actively involved in the social, cultural, and philanthropic life of the city. Her involvement enabled then-ambassador Koh to gain visibility, relevance and access through different social networks. While in the United States, Poh wore formal cheongsam to diplomatic functions, following the example of Mdm Kwa Geok Choo, wife of former Prime Minister Lee Kuan Yew. These cheongsam, inspired by the 1920s cheongsam worn by the Song sisters, were worn by Poh following her return from the United States. This cheongsam was worn at a function at the Istana whilst S. R. Nathan was president of Singapore.
