The girls' families told British lawmakers Tuesday they had no idea what the girls were planning, and said they were baffled by the teenagers' decision to leave their homes and families.
The three East London classmates -- Shamima Begum, 15; Kadiza Sultana, 16; and Amira Abase, 15 -- boarded a Turkish Airlines plane from London's Gatwick Airport to Istanbul on February 17. They are thought to have crossed the Turkish border into Syria within days.
Relatives also had harsh words for police, who they said failed to keep them informed after a close friend of the girls headed to Syria in December.
Amira Abase's father, Hussen Abase, told lawmakers at a hearing of the Home Affairs Select Committee that he had no idea his daughter was planning to go or that she might have been radicalized.
Sahima Begum, the older sister of Shamima Begum, said her sister had been into "normal teenage things," like watching "Keeping Up with the Kardashians," reading and playing games on her phone.
There was nothing to indicate she was radicalized, she said.
Fahmida Aziz, first cousin of Kadiza Sultana, said that if the family had spotted any signs of radicalization, "we would have been very effective in stepping in and querying" that thinking.
She also said she had no idea how her cousin accessed the money needed for the trip.
Committee chairman Keith Vaz said it was "every parent's nightmare that this should happen" and said he could only imagine the families' distress and anguish.
Police criticized over letter
The families' criticism of law enforcement hinges on a February 5 letter from the police which was given to the three girls to give to their parents, rather than being sent directly to the parents.
The families claim they were not told about a 15-year-old friend of the girls going to Syria weeks earlier -- and say that had they known, they might have been able to prevent their daughters from traveling too.
Metropolitan Police Chief Bernard Hogan-Howe apologized for his officers' failure to get the letter directly to the parents, in his testimony before the committee.
But he also pointed out the difficulties for police in conducting what was at that time a missing person inquiry for the first girl who left, with no sign that these three were planning to follow suit.
Hogan-Howe said police were reviewing their procedures in light of what had happened.
Assistant Commissioner Mark Rowley told the committee there was a "steady flow" of girls trying to travel to Syria, perhaps one or two a month.
He said subsequent police investigations indicated the three girls had paid in cash for their plane tickets to Turkey at a local travel agency, using money linked to the theft of jewelry from their families.
None of the girls was reported missing until several hours after the flight had left for Istanbul. However, the families' lawyer asked how they had managed, as minors, to board the flight without being challenged.
CCTV footage also later showed that the girls spent much of the next day waiting at a bus station on the outskirts of Istanbul -- raising more questions about why they were not spotted then and whether UK police had communicated effectively with Turkish authorities.
Rowley said that two people have been arrested in relation to child abduction in relation to the first girl who went missing, who has not been named.
Asked how the UK might be able to get the girls back, Rowley cited an incentive: As long as they're not connected to terrorist offenses, they'll be able to return to their families.
Rowley said police have no evidence that the girls have been involved in terrorism-related activities, and if that remained the case, they wouldn't be treated as terrorists upon their return.
Checklist found in bedroom
The list was reportedly found in the bedroom of one of the girls and handed to police after her family realized she was missing.
It detailed items to buy, such as underwear, a mobile phone and cosmetics, and estimated travel costs, apparently totaling £2,190 ($3,296). The biggest single cost was the three plane tickets to Turkey, the newspaper said, at just over £1,000.
The list, written on a page from a diary planner, had initials indicating which of the girls was to buy what or who the items were for. It's not clear where they would have gotten the money to meet the costs.
Over the weekend, the girls' families asked for an apology from London's Metropolitan Police over the force's handling of the case.
The police said in a statement Saturday that after the first girl went missing in December, a police officer spoke to seven of her school friends at Bethnal Green Academy -- including Shamima, Kadiza, and Amira -- as potential witnesses who might have information about the missing girl.
A deputy principal at the girls' school was present for the meeting and afterward contacted the parents of the seven girls, on the advice of police, and told them that the girls' friend, referred to only as "Girl 1," had been reported missing.
An officer who then spoke to the same group of girls on February 5 gave them the letters addressed to their parents asking for further help from their daughters, the police statement said. But not all the letters were passed on.
"With the benefit of hindsight, we acknowledge that the letters could have been delivered direct to the parents," the police statement said.
"However, the parents were already aware from the Deputy Head that Girl 1 had been reported missing, all the teenagers were all being co-operative, they were all being treated as potential witnesses and there was nothing whatsoever to indicate that they themselves were planning to travel to Syria."
Social media recruiter
Days before they left for Turkey, at least one of the girls allegedly contacted a young woman, Aqsa Mahmood, who left her home in Scotland to travel to Syria in 2013 and is accused of trying to recruit others via social media.
She has posted tips for girls and young women wanting to travel to Syria to marry jihadis, as she did. Her blog also has links to advice posted by another jihad supporter, which recommends that those traveling to Syria seek to pack the essentials but not too much, since they may need to move often and at short notice, while remaining inconspicuous.