We are a family (two sons 7 & 9) from Germany and want to visit my wife's family in Boston next summer. My wife was born in Iran and, as an infant, moved to Germany with her parents. At the age of 12, she became a German citizen with her own German passport. Before that, she didn't have her own passport but was included in her mother's passport.
During the ESTA process, there are important questions:
Have you ever been issued a passport or national identity card for travel by any other country?
I said NO.
Are you now, a citizen or national of any other country?
I said NO.
Have you ever been a citizen or national of any other country?
I said YES: Iran. Country of birth? IRAN
Her ESTA was approved!
However, I'm not clear whether she still needs a tourist visa because she was born in Iran and Iranian law says once an Iranian, always an Iranian citizen.