His grisly killing sent fresh shockwaves across the world six months after the 9/11 terror attacks.
For Mariane, then a journalist for French radio, it was enough at first to make life seem unsustainable. But she had no choice - she was six months pregnant with their first child.
"Not long after I started writing my book I had an email that said there were 103 babies who were not going to know their fathers because of 9/11," Pearl says from her home in Barcelona, 11 years after the murder of her husband, who was 39.
"The reaction in the US was that women wanted to shelter their kids from the world, they thought there was no hope. I disagreed because the question is not whether there is hope, but where to find it. It was true to Danny and it's true to me."
Pearl's search has inspired her work since. After she published her book, later turned into a film starring Angelina Jolie, she devoted her professional life to giving a platform to women fighting their own injustices. She travelled the world interviewing women for columns in Glamour magazine, later collected in her second book, In Search of Hope. Subjects included a former child sex slave in Cambodia who went on to rescue girls from forced prostitution, and Ellen Johnson Sirleaf, Liberian President and Africa's first female head of state.
Now 45, she manages Chime for Change, a new global movement raising funds and awareness for women's rights and empowerment. Its backers include former British Prime Minister Gordon Brown and his wife Sarah, Archbishop Desmond Tutu of South Africa and Beyonce Knowles, who will lead a fundraising concert in London this weekend. Concert proceeds will be invested in projects all over the world.
Pearl says she told Adam, 11, early on what had happened to his father. "I think the worst thing to do is hide it or censor it because it becomes more a source of anxiety. It's constantly there, that's the hardest part."
Her mission as editor of Chime's journalism platform is to allow women to inspire change from the bottom up. Running what she calls a journalism "laboratory", she gathers stories from contacts, organisations and news agencies based all over the world. She chose to focus on women because she is "convinced they offer more hope for the future". She also despairs at persisting gender inequality, and the failure of male-dominated media and governments to talk properly about issues affecting women.
"We generally look at women in a very patronising way; they are either heroes or victims. It's a way of belittling them in some way because this is an issue about power. Letting women express themselves or have more say is about giving up some of that power, and that's why the struggle is hard."
Her solution: let go and listen - and not just to one voice. Pearl finds hope in Malala Yousafzai, the Pakistani schoolgirl who defied the Taleban to fight for access to education. She was elevated to the pages of the New York Times and beyond, and then shot in the head, just surviving a Taleban hit. Hero status was sealed after her recovery in England when she was nominated for the Nobel Peace Prize.
"Even Malala herself is saying okay, there's a bunch of me out there. So are we going to manufacture a new Gandhi or Mandela, or do we need a number of great individuals who have such a strong sense of justice in their communities that, together, they're unstoppable?"
Women like Mercy Kumwenda, a 23-year-old health care worker from Malawi. When she came out in February, she made the front pages in a country that sees homosexuality as akin to Satanism. She had death threats and was disowned by her father, but would not be silenced. "I have managed to get to know of 45 lesbians in Lilongwe alone," she told Pearl in Malawi's capital. "I had to come out because it's clear so many of us will be forced into marriage or never find love."
Pearl believes we have reached a critical phase in feminism that will go over the heads of governments, however unsympathetic. "Change is not going to come from a world leader," she says. "Real change comes from inside. Politics will follow because, like big movements in history such as apartheid, we've reached the point where nothing can stop us, not even the Taleban."
Khalid Sheikh Mohammed, the main architect of the 9/11 attacks, confessed to Daniel Pearl's beheading in 2003, and is imprisoned at Guantanamo Bay. Ahmed Omar Saeed Sheikh is appealing against a death sentence handed to him in Pakistan for his role. Qari Abdul Hayee, was arrested in March. "Things take a lot of time but hopefully, we'll get to the point where it's over," she says.
Pearl, who was born in France to Dutch and Cuban parents, lives in Spain with Adam and Martin, a Dutch-Argentine businessman and her partner of five years. In interviews not long after Danny's death, Pearl talked about work as a form of revenge.
"I've suffered moments of deep solitude. But my determination and understanding of what I should do about what happened has never wavered because if I collapse now, they win."
