Thirteen of the girls joined the first lady and 18 White House staffers, including advisers Valerie Jarrett and Melody Barnes, in the State Dining Room to kick off the program, which Mrs. Obama said was one of her top goals on becoming first lady.
"We thought, what can we do to make the White House different, to make kids in our own new neighborhood know that the White House is a place for them?" she said.
Her voice cracking with emotion, Mrs. Obama said the program was started to let local kids "know that the president of the United States hears you and values you and cares about your growth and development."
The program is intended to inspire 10th- and 11th-grade girls from public and private schools in Washington, Maryland and Virginia by giving them access to accomplished women.
"It's also about understanding that all of us have had challenges and bumps along the way, and to know that there's just a level of moving through it that all of us have had to do," she said.
Mrs. Obama said that she and her husband, President Barack Obama, grew up in modest circumstances without a lot of access to power. But they did have parents and other people who had consistent interests in their lives. She listed her mother, neighbors and 5th-grade teacher as important mentors in her youth.
"We have some expectations from you as well," Mrs. Obama told the students. "That when you get to this position in your life that you do the same thing for somebody else."
The participating students were chosen by their school principals as the girls who could most benefit from the program, according to the White House. Monday's group will expand slightly.
The group will meet formally at least once a month through August, and mentors may check in more frequently.
The White House says a similar program for boys will be launched soon.
