Sharon Balkcom, raised on the scrappy streets of East Harlem, was in the third grade when her teachers realized that she had a gift for mathematics, said her mother, Rosalie, who was not surprised.

Ms. Balkcom, 43, the second of three children, attended some of the city’s most rigorous and selective secondary schools: Robert F. Wagner Middle School on the Upper West Side and the Bronx High School of Science. She received an M.B.A. from Pace University and a bachelor’s degree in political science from Colgate University.

Ms. Balkcom’s academic aptitude and varied education prepared her to tackle most jobs. She was a computer systems manager at Marsh & McLennan, where she had worked for about three years, her mother said. 'She was motivated,' said her brother Gordon, a publicist. 'Whereas I might need someone to kick-start me, she was self-motivated.'

As a child, that motivation helped Ms. Balkcom, a resident of White Plains, overcome teasing from neighborhood children about being a bookworm. 'She held her head up and continued to do what was right,' Mrs. Balkcom said. 'My husband and I brought our children up the best we could. We tried to instill in them the importance of having an education. We taught them that things were not handed to them. If they wanted something, they had to work hard to get it.'