Lateefah Simon got her first nonprofit job at 17, talking to young women on the streets of San Francisco about tough issues such as how to escape pimps and prevent HIV and drug abuse.

“I learned a very complex leadership style from working with young women in crisis, but who were brilliant and had more resiliency in their pinkies than the sociologists who would write about them or the law-enforcement officials who would lock them up,” she says.

The job paid $8.50 an hour, enough for Ms. Simon, a young mother, to quit her job at Taco Bell and go back to high school. It also set the stage for a remarkable career doing social good. Two years later, the Center for Young Women’s Development promoted her to executive director. At 26 she won a MacArthur Fellowship — aka a genius grant — for building the group into a national model for helping poor young women of color.

Ms. Simon went on to create the City of San Francisco’s first re-entry program to keep young offenders from committing additional crimes, and she served as the executive director of the local chapter of the Lawyers’ Committee for Civil Rights while still finishing her college degree.

Now, she is committed to nurturing the next generation of social-justice leaders. She spent the last 18 months creating Leading Edge, a three-year, $75,000 fellowship program, and is identifying young people with bold new ideas on issues such as juvenile justice. The fellows will be named in February.

Ms. Simon is also meeting with young activists leading Black Lives Matter, making grants and providing other assistance. She’s frustrated by philanthropy’s hand-wringing about how best to support fledgling grass-roots groups.

“The movement is moving at the speed of Twitter,” she says. “And we are moving at the speed of ants in quicksand.”

The desire to drive change bleeds into Ms. Simon’s personal life. She helps organize bone-marrow donor drives, in memory of her husband, Kevin O’Neil Weston, who died of leukemia in 2014. And she’s running for a seat on the Bay Area Rapid Transit board because she thinks reliable transportation is critical to fighting poverty.

“I want to be a part of the change-making process for every system that touches my life and my children’s lives,” she says. “So, hell yeah, I’m running for the BART board.”

Lateefah Simon, 38
Program Director, Rosenberg Foundation