Two of her younger brothers, Abdurahman and Omar, were held by the United States as enemy combatants in the Guantanamo Bay detention camp after being captured in Afghanistan in 2002.

Abdurahman Khadr was also detained, but he had claimed to have been working for the United States CIA when he was held as a detainee in Guantanamo Bay detention camp, 2002–2003.

In October 2010, her youngest brother Omar Khadr pleaded guilty to charges in a plea agreement, and was repatriated to Canada in 2012 to serve the rest of his eight-year sentence.

On January 31, 2016, Michelle Shephard and Peter Edwards, writing in the Toronto Star, reported that Zaynab had been apprehended, in Turkey for a visa violation.

[11] When police arrived eight days later to arrest her father on suspicion of involvement, Zaynab grabbed his rifle and screamed at them, while her mother barricaded the door.

[11] Six months after the couple began living in a rented Tehran apartment, Abdullah phoned his father-in-law to report that Zaynab was inconsolable at being separated from her family.

Her father asked the boys of the family to vote on whether he should give his consent to the marriage, and did so after Abdurahman and Kareem voiced their enthusiasm; the younger Abdullah and Omar abstained.

[11] The following year, Zaynab and her mother returned to Canada for several months late in her pregnancy, where she gave birth to a daughter, named Safia.

[11] He disappeared later that year, as did their younger brother Omar, not yet 16; she learned later that they were both being detained by the United States as enemy combatants at the Guantanamo Bay detention camp.

In 2003, Zaynab, her daughter and her mother stayed at a house in Birmal, Pakistan for two days, before their hosts grew wary of American jets overhead.

In her book Wanted Women Deborah Scroggins describes meeting Zaynab while she was a house-guest of Khalid Khawaja, in Islamabad, Pakistan, in 2004.

"[page needed] Although her passport had been revoked by the Canadian High Commission in Pakistan after her father was alleged to be a terrorist, Khadr returned to Canada on February 17, 2005 to be with her mother, and help the legal defence teams of her brothers Abdullah and Omar.

[19] When Zaynab returned to Canada, security officials, including Konrad Shourie, met her at the airport bearing a search warrant.

[23][24][25] On October 5, 2009, Isabel Teotonio, writing in the Toronto Star, reported on the extradition hearing for Zaynab's brother Abdullah Khadr.

[21] Although Zaynab has indicated a desire to one day return to Pakistan, her Canadian passport remained withheld, for many years, rendering her unable to leave the country.

[30] Zaynab has worked to arrange legal support for other Canadians accused of militant actions in the war on terror, notably attending the bail hearings and preliminaries for the men and youths arrested in Toronto in 2006.

In October 2008, Zaynab began an 18-day hunger strike on Parliament Hill, where she hoped to draw attention to the government's inaction in bringing her brother Abdurahman back to face trial in Canada.

The decision of Justin Trudeau's Liberal government to award Omar Khadr, an alleged former member of Al-Qaeda convicted of murder (notably, as a minor), with these funds has been highly controversial in the country, igniting resentment and outrage in a segment of the Canadian population.

On April 9, 2004, Maha and Abdulkareem used the family's savings to return to Canada;[36] The politicians Stockwell Day, Bob Runciman and John Cannis were among those in a public outcry calling for the Khadrs' citizenship to be revoked, and for the pair to be deported.

[39] In 2005, following the oldest daughter Zaynab's return to the country, Royal Canadian Mounted Police (RCMP) officer Konrad Shourie said, "The entire family is affiliated with al Qaeda and has participated in some form or another with these criminal extremist elements".

[40] A noted friend of the family, former Pakistani Air Force officer and ISI agent Khalid Khawaja, spoke in their defense; he said that they were being unfairly targeted by Canadian authorities because of a deference to the United States (who held their youngest son), and Islamophobia.

[42] In their 2008 report concerning Mahmoud Jaballah, Canadian Security Intelligence Service (CSIS) stated that Omar and his older brother Abdulkareem attended terror training camps.

[43] In late October 2010, Omar Khadr pleaded guilty to charges against him in a plea agreement before a Military Commission at Guantanamo, admitting to having received "one-on-one terrorist training from an al-Qaeda operative and that he threw the grenade that killed U.S.