A civil rights lawsuit that led to oversight by a federal court and to a settlement with the city last year has prompted changes in recruiting and led to an increase in the number of blacks and Hispanics graduating from the Fire Academy.

Mayor Bill de Blasio, a Democrat who took office last year, and his fire commissioner, Daniel A. Nigro, back the efforts, but the city faces a long road in remaking the department to be more representative of New York.

Ms. Kansfield is familiar with the sort of institutional resistance that long marked the Fire Department. The New York branch of the Reformed Church in America would not ordain her, despite her being deemed “fit for ministry” by her seminary professors. She was instead ordained through the United Church of Christ. (Because the two denominations recognize each other’s clergy members, she is able to preach in the Reformed Church.)

The Fire Department currently has seven chaplains — six of them Christian and one Jewish. Ms. Kansfield will be the eighth. Chaplains perform a variety of services: They provide counseling to firefighters and department personnel; they perform blessings and invocations; and they assist with notifying families in the rare instances when a firefighter is killed in the line of duty.

The chaplains, who receive a starting salary of about $20,000, work part time and are on call a few days a week. They wear the uniform of a chief, with special brass to signify their chaplaincy, and are issued emergency lights and sirens for their cars — in Ms. Kansfield’s case, a silver Toyota Prius.