By Mike Miller
Updated November 02, 2016 10:13 AM

After eight years serving as an artistic ambassador for Save the Children, which provides relief and support for kids in rural America and developing countries, Jennifer Garner has learned the importance of working in the field.

The actress, 44, now a trustee for the nonprofit, and her friend, the fund’s president and CEO Carolyn Miles, are among PEOPLE’s 25 Women Changing the World. While visiting Brooks Elementary in Duncan, Mississippi, the two women sat down to discuss their friendship and their fight for all kids to have a promising future.

The people that we tend to serve are people that are out of the way, the hardest to get to and nobody else seems to reach out and grab for. And that’s true in the U.S. as well,” Garner explains.

We want three things: We want kids to not die from preventable diseases; we want every child to get into school and have a high-quality education; and we want to protect kids from violence and harm,” Miles adds.

Following Miles’ lead, Garner has come to realize that the only way to accomplish these goals is to volunteer on the front lines. For instance, the actress recalls that when Ebola broke out, Miles was on the first plane to Africa. “All of us were saying, ‘You know what? We kind of need you. Can you maybe rethink going to middle of hell and just stay put here in Connecticut and we’ll help from afar?’ “

But Garner says, “Carolyn knows better than anyone, you have to go. You have to see it with your own eyes. You have to participate in the work that you’re doing. You can’t sit somewhere and just write emails. You have to actually go.”

Her emphasis on groundwork has led Miles all over the world. In Syria, the CEO has followed “the paths of refugees from the point of contact, to where they end up, to how they’re traveling, to what their education looks like for their kids,” Garner says, for example.

While Garner admits she’s not an expert in every facet of Save’s organization, she attributes her success with the fund to the hands-on approach she learned from Miles. “I don’t see myself as someone who’s an expert on poverty in rural America or who has a business degree and should be on a board of a huge organization like Save. But I do understand tackling a problem. And I do understand just diving in,” she explains.

“All I mean when I say that is I can tell myself, ‘Well, you can tackle this one email’ that I might be intimidated to write or I can tackle getting to Mississippi and covering my kids at home and making sure everything is set so that I can go and be with the kids here for a couple of days. I can tackle it. I’m not afraid to try. So that’s my word and that would be my word of encouragement, to anyone. You can make a difference if you’re just not afraid to tackle.”

WATCH: Jennifer Garner, Serena Williams, and Other Women Who Are Changing the World Share Words That Inspire Them

Beyond her work in the field, Garner says that being a mother has influenced the way she sees the world. While she does not “think you need to be a mother to connect to other mothers,” the actress and mom of three says that “becoming a mother just automatically crosses any boundary you might have with another woman. It’s like joining this huge, enormous global club. When you see somebody struggling, you instantly think, ‘Well, that could be me.’ “

She adds, “Family is the most important thing you could possibly have. But family isn’t just your mother, father, sisters, brothers, kids, aunts, uncles, when I go home to West Virginia, I go and see my family. And that is my ballet teacher, I go and see my best friend from growing up, her mom, I visited her in the nursing home, and I took my son and we went and saw her, just as if she were my mom. She’s so important to me. Family is somebody who has just reached outside of themselves over and over to help you and make your life better and with great patience as you have been in enormous pain and I have had a lot of people who have been very patient with me. So I see family as just an extension of yourself, however that may fall in your life.”