Boular was finally arrested on April 12 last year. But Boular went on to discuss the plans with her sister Rizlaine Boular, 22, and mother Mina Dich, 43, using coded language based on an Alice in Wonderland-themed Mad Hatters tea party.Picking up where Safaa left off, Rizlaine and Dich carried out reconnaissance visits around landmarks in Westminster and bought knives and a rucksack.On April 27 last year, fearing the attack was imminent, armed police moved in and, during the raid in Willesden Green, north-west London, Rizlaine was shot and injured.Rizlaine was jailed for life with a minimum term of 16 years, having admitted preparing acts of terrorism. Boular, one of the youngest women to be convicted of terrorism offences in the UK, betrayed no emotion as she was jailed.In mitigation her barrister, Joel Bennathan QC, said she had been “groomed” into radicalism when she was 15 but had since shunned Islamist extremism and no longer follows the Muslim faith.He said: “The environment in which this young woman became drawn into radical Islamist terrorism was a family which had the combination of a neglectful mother and an older, very radicalised sister,”Mr Bennathan said she is “no longer that type of person”, adding: “That’s the point about teenagers, they can change dramatically and fast.”Following the trial police said they feared this might not be the last terror plot to be masterminded by women in this country.Dean Haydon, the Metropolitan Police’s senior national co-ordinator for counterterrorism, said: “It’s difficult to say whether there will be others. But looking at what’s happened in other countries, there probably will be.” Her mobile phone, which she was using to contact her “husband” in Syria, was seized. She had downloaded videos of women wearing suicide belts.Boular began plotting to carry out a terrorist attack on the British Museum using the code words “tokarev” and “pineapple” for guns and grenades.She took delivery of a replacement phone hidden inside a heart-shaped chocolate box and using encrypted messages contacted 32-year-old Hussain from her sixth-form lounge and her bedroom. After Hussain was killed in a US drone strike Safaa discussed her plan with two undercover secret service officers posing online as extremists. Boular was first stopped by police on Aug 16 2016, on return from a holiday in Morocco. She admitted she wanted to go to Syria to marry Naweed Hussain, an Isil fighter. Her passport was seized, but since there was no evidence she planned to commit an offence she was allowed to return to her home in Vauxhall, south London. A heart-shaped box which contained a secret phone given to Safaa BoularCredit:Metropolitan Police/PA Boular’s ‘husband’, IS fighter Naweed HussainCredit:Metropolitan Police /PA An Old Bailey judge has jailed a teenager who was part of Britain’s first all-woman terror cell for life after rejecting claims she had renounced her Jihadist views.Sentencing Safaa Boular to a minimum of 13 years in prison Judge Mark Dennis QC said that despite being groomed by an Isil fighter the 18-year-old remained responsible for her actions.Boular was found guilty in June of two counts of preparing terrorist acts after she plotted with her sister and mother to attack tourists and Londoners at targets around the capital, including the British Museum and Palace of Westminster.Judge Dennis said: “In my view there’s insufficient evidence upon which it would be safe to conclude at this stage that the defendant is a truly transformed individual and the serious risk that she has posed hitherto has now evaporated.”Her views were deeply entrenched. However much she may have been influenced and drawn into her extremism, it appeared she knew what she was doing and acted with open eyes.” Court artist sketch of Safaa Boular appearing at the Old Bailey during her trial on terrorism offencesCredit:Elizabeth Cook/PA Dich, 44, was imprisoned for six years and nine months with an additional five years on licence for helping her. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.