Barack Obama's Sister Reflects on Rare Childhood Photos and Lessons Learned About Leadership & Love

The roots of Barack Obama‘s family tree grow deep and wide — Hawaii, Kansas, Kenya, Indonesia — and his post-presidential life has been similarly expansive.

On Friday morning, he and younger sister Maya Soetoro-Ng will appear in Malaysia at his eponymous foundation’s annual leadership summit. Their talk, which can be watched here, will focus on what it means to lead and the multicultural childhood they shared, which inspired the belief that leadership — good leadership — is fearless, humble, collaborative and creative.

“We’re really looking for leaders who are embedded, who are grassroots leaders who understand that although they may have a great many skills and accomplishments, that we accomplish more together,” Soetoro-Ng says.

An adviser to The Obama Foundation, Soetoro-Ng, 49, spoke with PEOPLE ahead of her Friday conservation with her brother. She previewed some of the childhood memories and rare photos that she and Obama, 58, will discuss. And she reflected on the legacy of the mother who raised them both — who was always “brave about loving people who were very different from her.”

• First Lady Michelle Obama has been on her own trip to Vietnam this week, to focus on girls’ education. For more, subscribe now to PEOPLE or pick up this week’s issue, on newsstands Friday.

Hawaii and Back Again

Of the photos that will be shown at Friday’s event, Soetoro-Ng points to three that show “our family’s complexity and hybridity, but also the importance of this work and connecting the United States with the Asia Pacific region.”

Last year, the foundation mentored leaders in Africa. This year’s class of 200, from the private and public sectors, come from 33 nations and territories across the Asia-Pacific region who have been meeting in Kuala Lumpur this week.

“We can’t afford to move in isolation,” Soetoro-Ng says. “We need to be promoting and supporting rich dialogue and understanding. And so we hope that this program is a demonstration of that commitment between the United States and the Asia-Pacific region. Our desire to continue to support and learn from one another and to grow with mutual health and happiness and peace.”

The first photo she talks about is the earliest, in Hawaii, “an important starting point” where “so much of our family story takes place.”

“We really feel that although we’re in Southeast Asia now that so much of our program is infused with the spirit of aloha and the Pacific and we really want to uplift the Pacific Islands and shine a light on the many solutions that the Pacific Cup presents — indigenous wisdom and lots of sustainable and environmental connection and reverence for nature,” Soetoro-Ng tells PEOPLE.

The first childhood photo shows Obama with their mother, Ann Dunham, in the mid 1960s, and Soetoro-Ng is almost certain it’s when their mom graduated with her bachelor’s degree in anthropology. She went on to earn two graduate degrees in the field.

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“It would have been right before she made that long journey to Indonesia,” Soetoro-Ng recalls. Obama was about 6. Dunham was divorced from his father and later moved with him to Indonesia to live with her second husband, Soetoro-Ng’s father. She was born in Jakarta in 1970.

From their mother, “a pioneer in microfinance and in supporting women and children’s village and rural cottage industries throughout Asia,” Obama learned his “sense of compassion and social justice and inclusion,” his sister says.

In their new home, far away from their old one and her Kansas family, Dunham “built bridge to give out the experiences from home that were familiar in a place which was different,” Soetoro-Ng says.

“I remember when it was, in Indonesia, hard to get Christmas things, would get a sort of scraggly-looking pine tree and red and green construction paper because ornaments were hard to find back in those days,” Soetoro-Ng says. “And she would string the tree with red and green construction paper chains put together with Elmer’s glue and then she would hang red and green chili peppers all over the tree, which was, I thought, kind of a fun way to make the best of limited resources.”

Even decades later, from his early years in Indonesia, “embedded” in Obama’s leadership style is “that balance between rugged individualism and sort of a lot of Asian-specific collected community sensibilities,” his sister says.

“He understood by virtue of those four years of childhood here in Indonesia that beauty can be found in unexpected places and people, with little in the way of resources,” Soetoro-Ng says.

(And, she notes, “It’s funny, he’s not a huge eater — that’s why he’s so lean — but he gets very excited about Southeast Asian food. He will throw down.”)

Even those same chilis his mom hung popped up on an Obama family Christmas tree years later, in their way — this time as ornaments, his sister says.

The second of three photos Soetoro-Ng wants to talk about is from June 1972 and shows her and Obama with their mother, Soetoro-Ng’s paternal grandmother and the family’s nanny at the Prambanan, a Hindu temple in Indonesia, which is one of the United Nations’ World Heritage Sites.

“We spent a lot of time during those years scrambling around and on this temple,” Soetoro-Ng says. She and Obama went back to Prambanan in recent years with both of their families.

“ is sort of emblematic of the deep connection that we feel to the art and the beauty and the culture of the Asia Pacific region,” she explains, “and it demonstrates that our childhood learning was not simply through books. It was very much in place of community. And I love that these places are being also protected now.”

The third photo is back in Hawaii, where Obama attended middle and high school. The photo was taken around late 1972 or 1973, Soetoro-Ng says. It shows the two of them with their mother and maternal grandfather in a place that has been a constant in a family with many different homes and many different pasts.

“My brother has made a commitment to taking his kids to Hawaii every single Christmas,” Soetoro-Ng says.

With Malia and Sasha both in college this year, he and wife Michelle have been traveling in Asia recently — Tokyo, Vietnam, Kuala Lumpur, Singapore — before joining their girls in Hawaii.

RELATED: Obama Delivers Message of Tolerance as He Closes Out Nostalgic Visit to Boyhood Home — ‘Indonesia Is a Part of Me!’

Back home, Soetoro-Ng says, Obama reconnects with old school friends, sees extended family and relishes local traditions. (Even though he abstains from most sugar, he allows himself shaved ice with the kids.)

There’s a bonfire, a big luau and guitar-playing, plus hiking and eating.

“There’s always time at Hanauma Bay, where our mother used to take us,” Soetoro-Ng says.

A Tearful Gift and Wandering the World Now

When Obama was preparing to leave the White House, actually, staffers there — with some Obama family — got together on a sentimental gift to evoke his mother, who died in 1995.

“Kids, staff all pitched in and bought a bench, which they inscribed in memory of our mother that sits there now ,” Soetoro-Ng says. “It’s a place that looks out over the bay and where he can go and sit and reflect and contemplate.”

“He got teary when he got that gift,” she says. “It was so touching.”

RELATED: Michelle Obama Looks Back on the ‘Panic,’ Vulnerability & Gratitude of Her Record-Setting Year

Since leaving office, Obama’s life has certainly slowed, though he’s far from retirement. Wife Michelle published a record-breaking memoir, Becoming, last year, followed by a popular book tour. He’s writing his own memoir. Both are focused on the foundation’s work, including fostering the next generation of leaders.

As Mrs. Obama told Today this week: “Replacing ourselves, getting out of the way and letting some young people sit in some of these seats — we’ll be doing that, Barack and I, for the rest of our lives.”

There is also time, more and more, for travel on their own. The whole world, one person at a time.

“My brother … he’s a wanderer,” Soetoro-Ng says. She adds: “I think that if he had the choice, he would just set out and spend hours wandering. He is definitely not an in-a-hotel-spa tourist. He is definitely somebody who visits markets  sitting on the steps listening to street musicians. He loves museums, always did, and would definitely go see different sites, churches and temples. He would spend a majority of his time, if he could, just exploring.”