It was only later, when she was a freshman at University of California, Berkeley that Castro read a news article and realized that Laurene was Silicon Valley royalty, the wife of Apple's co-founder, Steve Jobs.
"I just became 10 times more appreciative of her humility and how humble she was in working with us in East Palo Alto," Castro said.
The story, friends and colleagues say, is classic Laurene Powell Jobs. Famous because of her last name and fortune, she has always been private and publicity-averse. Her philanthropic work, especially on education causes such as College Track, the college prep organization she helped found and through which she was Castro's mentor, has been her priority and focus.
Now, less than two years after Jobs' death, Powell Jobs is becoming somewhat less private. She has tiptoed into the public sphere, pushing her agenda in education as well as global conservation, nutrition and immigration policy. Last month, for example, she sat down for a rare television interview, discussing the immigration bill before Congress. She has also taken on new issues such as gun control.
"She's been mourning for a year and was grieving for five years before that," said Larry Brilliant, president of the Skoll Global Threats Fund who is an old friend of Jobs'. "Her life was about her family and Steve, but she is now emerging as a potent force on the world stage, and this is only the beginning."
She is doing it her way, though.
"It's not about getting any public recognition for her giving; it's to help touch and transform individual lives," said Laura Arrillaga-Andreessen, a philanthropist and lecturer on philanthropy at Stanford who has been close friends with Powell Jobs for two decades. She is also the daughter of a wealthy real estate developer in Silicon Valley and the wife of Marc Andreessen, the venture capitalist.
"If you total up in your mind all of the philanthropic investments that Laurene has made that the public knows about," she said, "that is probably a fraction of 1 per cent of what she actually does, and that's the most I can say."
While some people expected Powell Jobs to start a foundation in Jobs' name after his death, she did not, nor has she increased her public giving.
Instead she has redoubled her commitment to Emerson Collective, the organization she formed about a decade ago to make grants and investments in education initiatives and, more recently, other areas.
"In the broadest sense, we want to use our knowledge and our network and our relationships to try to affect the greatest amount of good," Powell Jobs said in one of a series of interviews with The New York Times.
Still, the fortune she inherited, making her the world's ninth-wealthiest woman, according to the Bloomberg billionaires index, has catapulted her into the upper echelon of global philanthropists. That has led to certain expectations.
Powell Jobs has a net worth estimated at $11.5 billion, according to Bloomberg, most of it in shares of the Walt Disney Co. Jobs helped found the animation studio Pixar, which Disney acquired in 2006 and paid for in stock. With 131 million shares, worth about $8.7 billion, the Laurene Powell Jobs Trust is Disney's largest shareholder with a 7.3 per cent stake in the company, and she has benefited from the stock having more than doubled since her husband died in October 2011.
Jobs also owned 5.5 million shares of Apple at the time of his death, and it is unclear whether she has sold her position.
"She knows that she is in an unusual position and has the standing to have a major impact on the world stage," said Peter Seligmann, chief executive of Conservation International, on whose board Powell Jobs sits. "It will be fascinating to watch the choices that she makes."
Like many technology titans, her husband was criticized for not giving away as much money as he could. Jobs did not give publicly during his life - although there have been rumours of at least one major anonymous gift, to a hospital - and Apple has been panned for not having a charitable arm.
He also declined to sign the Giving Pledge, the organization started by Warren E. Buffett and Bill Gates to persuade the country's richest families to vow to give away at least half of their fortunes. During the interview, Powell Jobs, who still wears her diamond wedding ring, would not discuss her husband or her children. When asked whether she would join the Giving Pledge, she demurred.
"Whether someone signs something is not what's important," Powell Jobs said. "It's what they do and how they do it that matters."
Powell Jobs, 49, grew up in West Milford, N.J., and earned an undergraduate degree from the University of Pennsylvania. She worked for three years at Goldman Sachs as a fixed-income trading strategist. Her boss was Jon Corzine, who would go on to run the firm and become governor of New Jersey. After Goldman, she attended Stanford Business School. In 1989, when Jobs visited the school to give a speech, he found himself seated next to her.
"I looked to my right, and there was a beautiful girl there, so we started chatting a bit while I was waiting to be introduced," Jobs told Walter Isaacson, the author of the biography "Steve Jobs."
They went out to dinner that evening, married two years later, and together had three children. Jobs died at 56 after a long battle with pancreatic cancer. Powell Jobs, a food lover, lives with her children in the same unpretentious red brick home she and Jobs bought two decades ago, where they raise bees and send friends Christmas baskets with hand-labelled Mason jars of honey.
Powell Jobs is best-known in the education field for College Track, which she started in 1997. The group helps prepare low-income students from underserved communities for college, providing rigorous academic training and extracurricular activities. The program, which operates in a number of locations including East Palo Alto and New Orleans, has trained more than 1,400 students and sent 90 percent of them to college.
Last year, to be with her grieving family, Powell Jobs decreased her board seats to five from eight; but she also became a trustee at Stanford, which is near her home in Palo Alto.
Her involvement with immigration flowed from College Track. In its early years, a number of her students in the program were teenagers who had come to the country, unauthorized, at a young age and finished high school, but then could not obtain citizenship or receive any state or federal funds for college.
"This continues to be a purgatory that they find themselves in," she said in an interview. "It is one of these issues that seems discordant with what our country stands for."
Powell Jobs has become a leader in pushing for decade-old legislation known as the DREAM Act, a measure that would provide legal status for immigrants who arrived in the country as young children. In December she enlisted the Academy Award-winning documentary filmmaker Davis Guggenheim to make a documentary about immigration. The two had met through their work in education; Guggenheim's most recent film, "Waiting for Superman," examined the crisis in America's public schools.
"Laurene asked me how much time I needed to make a movie, and I told her about a year and a half," Guggenheim said, "but she said that she needed something done in three months because the legislation was coming up for a vote."
So instead of a creating a big feature with a broad theatrical release, Powell Jobs commissioned a 30-minute film, "The Dream Is Now," which is viewable online and being shown at college campuses across the country. Last month Powell Jobs and Guggenheim travelled to Washington with several young immigrants and their families who were featured in the film; the purpose of the trip was to screen the documentary for a group of lawmakers on Capitol Hill.
Powell Jobs said that, while trying to make change in Washington can be frustrating, she remains devoted to her causes.
"Despite the setbacks and the sometimes obstreperous political processes, once we are committed to working in a field where we can help advance knowledge or more equal opportunity, we cannot quit," Powell Jobs said. "I am so motivated by the stories of their students and their families, and I don't give up because they don't give up."
In December, Powell Jobs hired Russlyn H. Ali, who was assistant secretary for civil rights at the U.S. Education Department, to oversee education grants and investments at Emerson Collective. The name of the group pays homage to Emerson's essay "Self-Reliance."
Powell Jobs' work is not limited to domestic issues. She has supported numerous causes in Africa and has visited the continent several times. In 2010, she travelled to Congo with Ben Affleck and has provided support to his organization, the Eastern Congo Initiative. Last year, as a board member of Conservation International, she travelled to Botswana for a meeting of sub-Saharan Africa heads of state.
"She's a very private person who might be more comfortable being in the back," Seligmann said, "but she's a smart, amazing communicator who is also very effective in the front."