[aruanan]

because his mother -- not yet 19 at the time of his birth -- would not have had a sufficient number of years as an adult citizen, according to the laws prevailing at the time, to pass on "natural born citizenship" automatically.

No, his mother would not have had 10 years as a U.S. citizen, 5 of which had to be after the age of 16. The "adult citizen" doesn't enter into this at all because, at the time, one wasn't an adult until the age of 21. So his mother, at the time of his birth, was, according to Michelle Obama, an unwed minor.

[Red_Devil 232]

The statute (law) referenced specifically states the age 16 and does not reference the term "adult citizen"!