Sarah Nafi was the Indonesian grandmother of one of the owners. She was born in 1904 and was originally from the island of Roti, in eastern Indonesia. Around 1920 she lived on the island of Timor, in Sulamu near Kupang. There she met the young Dutch government official Max Eduard Louis Israel (Medan 1895) who started his career in the Dutch colonial administration in 1919. Sarah was probably the housekeeper and "njai" (concubine) of Max.

Although not married, two children were born: a daughter, Nelly (1922) and a son, Max junior (ca. 1923). Max Israel later married a Dutch woman and separated from Sarah. Nelly was separated from Sarah as well and went in the late twenties to the Netherlands to grow up with foster parents in The Hague. She would stay forever in the Netherlands and would never see her mother Sarah again. Her younger brother stayed with his mother in Indonesia. Sarah later married an Indo-European, Daniel Tielman, and had seven children and lived a happy life in Bima on the island of Sumbawa. She deceased in 1959 and  is buried there in the Christian cemetery where her grave still can be found. Max Israel continued until Independence his administrative duties in the Dutch East Indies. His last position there was his appointment as Assistant Resident in Singaraja, Buleleng Regency. He left Indonesia in 1946 and died a few years later in The Hague in 1951.

A copy of the only known portrait of Sarah Nafi is visible in the living room of the house that bears her name as a tribute.