İnan was one of six or seven adoptive (or foster, sources differ) daughters of Kamal Atatürk (1881-1938), the founder of modern Turkey (see also: Sabiha Gökçen). He also adopted a son and fostered two other boys. She was adopted in 1925.
She was a professor of history at the University of Ankara before and after World War II, and conducted anthropometric and linguistic studies of Turks and Kurds in the 1930s.
Other adopted and foster children of Atatürk and his wife were Latife Hanim Usakligil (1898-1976), Abdürrahim Tuncak (born 1908: an engineer), Zehra Aylin (1914-36), Rukiye Erkin (born 1920: married a military officer), Nebile Hanim (1910-43: married an engineer), and Ülkü Dogançay (born 1933: married a military officer).