Yes that’s correct. Stanley Ann Dunham would not have qualified. She would have been three months too young. She was born on November 29th and her son was born on August 4th. She would have needed to be 19 and she was 18 and 9 months.
But the state of Hawaii says that he was born there, so the point is moot.
Except the state of Hawaii does not OFFICIALLY say he was born there. Various state officials assert he was born there, but that tiny little thing called "Proof" has never been provided, and indeed they absolutely and categorically REFUSE to provide the proof.
Their statements and assertions do not constitute any compelling evidence of where he was born, it's just that people who wish to regard it as proven accept them at face value instead of being intellectually honest about it.