Helena Nobles-Jones in 2010. (Mark Gail/WASHINGTON POST)

Helena Nobles-Jones, a teacher and administrator in the Washington, Baltimore and Prince George’s County, Md., school systems who retired after 12 years as principal at Charles H. Flowers High School in Springdale, Md., died March 15 at a nursing center in Silver Spring, Md. She was 71.

The cause was cancer, said her daughter, Kyva Jones.

Mrs. Nobles-Jones began her career in education as an English teacher in the D.C. public schools in 1967 and retired 30 years later as superintendent of middle and junior high schools for the D.C. system.

She missed the daily interaction with students and teachers and soon went back to work as principal at Northern High School in Baltimore. Two years later, she was recruited as the first principal of the new Flowers high school, a comprehensive science and technology magnet school with a 2,700, all-minority enrollment.

In this role, she told The Washington Post in 2005, she spent much of her time watching teachers in the classroom and writing evaluations. “I’m very attuned to instructional effectiveness,” she said. “I stay in their face.”

She also recognized the obstacles that confronted her teachers. “We might as well deal with the facts of it,” she told The Post. “We’ve got kids moving from language arts into English who don’t know the difference between a subject and a verb.”

Under Mrs. Nobles-Jones’s leadership, Flowers, named for a member of the Tuskegee Airmen, was consistently near the top in most test scores used to measure educational achievement in Prince George’s County. But it also had the range of difficulties of many large high schools — isolated cases of sexual abuse of students by staff members and students fighting in hallways.

She retired from Flowers in 2012. The school’s auditorium was named for her when she stepped down.

Helena Nobles was born into a sharecropping family in Lenoir County, N.C., on April 15, 1945. She was the third of eight daughters whose father had left school after the third grade and was determined that his children would get an education. They did.

She was valedictorian of her high school class and graduated in 1967 from North Carolina Central University, a historically black college in Durham, N.C. In 1975, she received a master’s degree in education administration from Ohio State University.

In her years with the D.C. school system, Mrs. Nobles-Jones was a principal at Roper and Hart junior high schools, Mary Church Terrell Elementary School and Ballou Senior High School.

Her husband of 38 years, Tony Jones, died in 2015. Survivors include her daughter, of Bowie, Md.