WASHINGTON — Paula Broadwell, whose affair with the nation’s C.I.A. director led to his resignation on Friday, was the valedictorian of her high school class and homecoming queen, a fitness champion at West Point with a graduate degree from Harvard, and a model for a machine gun manufacturer.

It may have been those qualities — and a string of achievements that began in her native North Dakota, where she was state student council president, an all-state basketball player and orchestra concertmistress — that drew the attention of David H. Petraeus, the nation’s top spy and a four-star general, as the two spent hours together for a biography of Mr. Petraeus that Ms. Broadwell co-wrote.

Ms. Broadwell’s name burst into public view on Friday evening after Mr. Petraeus resigned abruptly amid an F.B.I. investigation that uncovered evidence of their relationship.

But Ms. Broadwell was hardly shy about her interactions with Mr. Petraeus as she promoted her book, “All In: The Education of General David Petraeus,” in media appearances earlier this year. She had unusual access, she noted in promotional appearances, taping many of her interviews for her book while running six-minute miles with Mr. Petraeus in the thin mountain air of the Afghan capital.