[2] Pfeiffer entered a novitiate to become a Roman Catholic nun, leaving after six months.

Pfeiffer started her career at IBM as a systems engineer trainee.

In 1966, Pfeiffer was appointed by President Lyndon B. Johnson to serve as the first female White House fellow, until 1967.

Pfeiffer solved an internal criminal scandal, reduced the NBC board of directors from eighteen to nine members, and reorganized the news division.

However, her staff found that her memos were arrogant, that she did not delegate responsibility, and they disliked her wholesale replacements in the finance, personnel, and technical areas.