Begum fled to Syria in 2015 when she was only 15 years old. She vanished during Easter break along with Kadiza Sultana and Amira Abase, two other schoolgirls from the Bethnal Green area of east London. The trio travelled from London's Gatwick airport to Turkey, and then made their way to Syria.
The case stunned Britain. The young women were bright and came from seemingly stable and happy families. Their fleeing was seen as a warning of the lure the Islamic State could have for young Western women.
Sultana is thought to have died in an airstrike in 2016. The fate of Abase is unknown.
Her father, Hussen Abase, told Sky News on Thursday that the girls had "made a mistake" and should be forgiven.
"I'm not the same silly little 15-year-old schoolgirl who ran away from Bethnal Green four years ago," Begum said in the interview with the Times.
Begum said that when she arrived in Raqqa, she went to a house for brides-to-be and "applied to marry an English-speaking fighter between 20 and 25 years old." Within 10 days, she was married to a 27-year-old from the Netherlands. They had two children who died of malnutrition and disease.
She said life in Raqqa was mostly "normal," although "every now and then there were bombs and stuff."
She also said that she didn't regret going to Syria and wasn't fazed when she saw the severed head of one of the Islamic State's victims.
Wallace told the BBC that everyone who takes part in the conflict in Syria or Iraq must be "prepared to be questioned, investigated and potentially prosecuted for committing terrorist offenses."
He also said that he wouldn't put British officials' lives at risk to "go and look for terrorists or former terrorists in a failed state. There are consular services elsewhere in the region and the strong message this government has given for many years is that actions have consequences."
Anthony Loyd, the Times correspondent who tracked Begum down in a refugee camp in northern Syria, cautioned about judging her too quickly. He told the BBC she was a "15-year-old schoolgirl who was groomed and lured to the caliphate, and four years later, with that background, she is an indoctrinated jihadi bride."
He also said that she "had no regrets, she was calm and composed but she was also in a state of shock - she had just come out of a battlefield, nine months pregnant, many of her friends dead through airstrikes and all the rest of it - so I wouldn't want to rush to judge her too harshly. We must remember she was a 15-year-old schoolgirl when she left the U.K."