New York City's first lady Chirlane McCray requested a deferment Thursday from jury duty in Brooklyn, saying last-minute appearances relating to her duties may make it hard to serve in court until the end of her husband's first term in 2018, her spokeswoman said.

Mayor Bill de Blasio separately said his wife can serve this fall but first must help prepare the couple's children, Chiara, 19, and Dante, 17, for college.

"I think every citizen has a right to ask for a postponement, but they must serve," de Blasio said at an unrelated event in the South Bronx. "She's going to serve in October after she gets her children to college."

McCray's spokeswoman Erin White later clarified that the first lady would be willing to serve as early as October.

McCray, who is chair of the nonprofit Mayor's Fund to Advance New York City, is a key advisor to her husband's administration.

A U.S. District Court official said that McCray did not have to serve in Brooklyn because she and her family now reside in Manhattan at Gracie Mansion.

"She was excused from jury duty because her residence has changed, and she's no longer in our district," the court's district executive Eugene Corcoran told Newsday.

McCray went to the Eastern District of New York courthouse Thursday morning to request a deferment. 

The de Blasios still vote in Brooklyn, where they lived for years in a Park Slope row house until they moved into the mayoral mansion on the Upper East Side in summer 2014.

The earliest McCray and her family would return to Brooklyn is January 2018, after de Blasio's first term ends. He has said he will run for re-election.

McCray is shaping mental health initiatives in the city, including "NYC Safe," aimed to steer people who are emotionally disturbed and prone to violence toward mental health services.

Chiara de Blasio this fall will be a senior at California's Santa Clara University. Her brother, Dante, will start his freshman year at Yale University.