Sheryl Sandberg and Priscilla Chan

THE NEW SCHOOL: Priscilla Chan has been a teacher, a doctor and can now say she runs a school.

Chan, who is married to Facebook cofounder and chief executive officer Mark Zuckerberg, talked about the K-12 school she helped open in August in East Palo Alto, Calif., along with what got her into public service, during a brief Q&A with Facebook chief operating officer Sheryl Sandberg today at Fortune’s Most Powerful Women Summit.

“The school’s really a continuation of my work as a pediatrician,” she said. “When I began my practice, I said I’m going to be a pediatrician that really thinks about and understands a child’s educational trajectory.”

She recalled an encounter with a patient in second grade who was not only struggling in school but also had a seizure disorder. As Chan looked into the child’s case more thoroughly, she found out the child — who had missed 150 days of school — had been exposed to extreme domestic issues that manifested into behavioral problems. The lack of communication between the school and health-care providers is something she hopes her school, called The Primary School, can help solve. The facility is still new, having opened roughly nine weeks ago.

Chan, who is the first in her family to graduate from college, said it was teachers who helped her pave the way to Harvard. It was at that point, she decided to make public service a major factor in her life.

“It’s incredibly important that Mark and I invest now, that we take risks in making big, important investments that may take 25, 50, 100 years to pan out,” she said.

Chan and Zuckerberg last year created the Chan Zuckerberg Initiative, inspired by the birth of their daughter Max Chan Zuckerberg, during which time they said they planned to donate 99 percent of their Facebook shares, valued then at about $45 billion, to charitable causes during the course of their lives.

The pair pack a powerful punch of skill sets they bring to CZI that in turn also challenges and motivates the other.

“We push each other in different ways,” Chan said. “It can be uncomfortable at times, but it’s really fun.”

The session also included a rapid-fire set of questions from Sandberg in which the crowd learned Chan’s real life heroine is Ruth Bader Ginsburg, Max’s first word was dog and two racks of baby back ribs are Zuckerberg’s favorite thing to cook for her. “That’s the Mark special,” Chan told a laughing crowd.