In the 1950s women had three primary professional career choices if they planned to work outside the home: nurse, teacher, and secretary. These were all supportive roles in which women were viewed as natural caregivers — an assumption built around motherhood as a woman’s primary role in life.

Today, virtually any career choice is available to women, including careers in leadership. But leadership brings great expanded responsibility as well. If you plan to be president one day, Ms. Ross argues, you should live each present day as if you will be president one day, and she offers practical advice on what that means.