When Shennel E.P. Henries was a little girl growing up in Liberia, maybe 5 years old, she remembers seeing a woman speaking out to get help for people who needed it. For people displaced by the country's civil war. For homeless people. For kids who didn't have enough to eat.Henries told her mom she wanted to be just like that lady.And that's a dream that she hasn't given up. This week, Henries, now 19 and a college student in Monrovia, was in Washington, D.C., as part of Girl Up's annual leadership summit.Girl Up, a project of the U.N. Foundation, a global campaign to promote the rights of adolescent girls. This year, 400 teenagers and young women came from 35 states and 24 countries, including France, Rwanda and New Zealand, came to the three-day summit. They're the leaders in Girl Up clubs. They took workshops like "Fill Your Cup: Avoiding Activist Burnout." And they lobbied members of congress to support a bill called "Protecting Girls' Access to Education in Vulnerable Settings Act," which, among other things calls for "safe primary and secondary education for displaced children" – a timely measure in this era of unprecedented numbers of refugees.To learn more about the youthful activists of Girl Up, we spoke with Henries and two other Girl Up leaders: Kate McCullum, 22, a recent St. Louis University grad from Tulsa, Okla., and Mariana Anaya, 17, a high school student from Monterrey, Mexico.Role modelsFor Henries, it started with that advocate she saw as a young girl. "I wanted to save the world and speak on behalf of issues that matter." But her number one role model is her mom, who made sure Henries and her siblings stayed in school. Michelle Obama is a close second.For Anaya, it's her grandmother, a politician in Mexico who focuses on international relations and gender equality: "She taught me about empowerment. She was [my] inspiration. At school, I was always the girl who stood up and tried to inform my classmates about feminism."What they'd like to change.Henries wants to stop child marriage: "You are not going to school. You have to take care of your home, you have to have kids."McCullum is struck by "how many girls around the world couldn't go to school." Learning about that issue from the documentary Girl Rising, she realized "how I took my own education for granted." As a college graduate, she hopes to work in the field of sexual health in Oklahoma, making sure girls and women have access to sexual health education.Getting boys to join the movement.Male friends don't always understand the need for a Girl Up movement, says Anaya. "They have this mentality of "Oh, why isn't there a Boys Up?" Her club has one male member. A girl had called him out for his anti-women comments. "He just was so shook" about her remarks, says Anaya, that he said he was going to do something and he did – "He joined our club." Advice for budding activists "As long as you have your voice, you have everything," says Henries. "You can speak your mind about the things that are troubling you." Copyright 2018 NPR. To see more, visit http://www.npr.org/.