Safaa Boular's sister and mother have also been jailed
An 18-year-old woman has been jailed for 13 years in Britain for planning terrorist attacks in London with her sister and mother.
The attacks were thwarted last year by counter-terrorism police and security services.
18-year-old Safaa Boular, of south-west London, was sentenced two terms of life imprisonment for two counts of preparation of terrorist acts.
She must serve a minimum of 13 years' imprisonment.
Her sister, Rizlaine Boular (22) and mother Mina Dich (44) both previously pleaded guilty to preparation of terrorist acts.
Rizlaine was sentenced on June 15th to life imprisonment and ordered to serve a minimum of 16 years.
Mina was also sentenced on June 15th to an extended sentence of 11 years and nine months - this is made up of six years and nine months' imprisonment and an additional five years on licence.
Deputy Assistant Commissioner Dean Haydon, said: "This investigation started with Safaa and her attempts to travel out to Syria, marry a Daesh fighter and support their terrorist activity.
"Having been prevented from travelling to Syria, she then set about plotting an attack in the UK but her plans were being covered by the counter terrorism network and security services.
"After Safaa was arrested and charged, her mother and sister tried to pick up where she left off. But again, working with the security services, we tracked their plans and stopped them before they were able to put them into practice.
"All three women were filled with hate and toxic ideology and were determined to carry out a terrorist attack.
"Had they been successful, it could well have resulted in people being killed or seriously injured.
"But thanks to the work of the security services and counter terrorism police, their plans never came to fruition."
An investigation was originally in August 2016, when police officers spoke to Safaa during a port stop on her return to the UK from a trip to Morocco.
At this point, Safaa - who was 16 at the time - made indications that she was planning to travel to Syria to join Daesh.
Two days later on August 22nd 2016, Mina reported them both as missing.
Further enquiries led police to find and arrest both Safaa and Rizlaine at a hostel in north-west London.
Both admitted that they were planning to travel to Syria in order to live under the Daesh regime, but insisted they simply wanted to live there peacefully and had no intention to carry out terrorist acts.
Officers seized mobile phones and digital devices from the sisters, and they found several conversations between Safaa and a British national who was fighting for Daesh in Syria.
The conversations showed that Safaa was planning to marry the fighter and included discussions between them about her wearing a suicide belt.
She was charged on April 12th 2017 with preparation of terrorist acts.
However while on police bail, Safaa remained in contact with the person she planned to marry in Syria.
It was during this time on bail that Safaa shifted her attention from travelling out to Syria to committing an attack in the UK.