A young woman who knew about her friend's imminent plot to launch a knife attack on Westminster has been jailed for two years and four months.
Khawla Barghouthi, 21, also faces deportation to Tunisia after she admitted failing to disclose Rizlaine Boular's Islamic State-inspired plan.
Boular, 22, had discussed and even practised her proposed knife attack at Barghouthi's home in Willesden, north-west London, shortly before her arrest on April 27 last year.
Laughing as they discussed plans
In a bugged conversation, the women were heard laughing as Boular talked about her fears that she might "flop so badly" and cut her arm by accident.
When armed police swooped to arrest them, Boular shouted "F*** you" and was shot by an officer, who thought she had something in her hand.
In mitigation, Michael Mansfield QC said Barghouthi came to Britain at the age of 11 from Tunisia knowing no English but excelled at school and aspired to a caring profession.
When she met "disturbed" Boular, she lent her a "hand or a shoulder", not knowing how serious she was, he argued.
Of her banter with Boular on the day of the planned attack, married Open University student Barghouthi said: "I did not believe the person I was with was actually going to go through with anything.
"When I read the transcript I was horrified how it sounds. What I can say, at the time it was extravagant talk and very stupid fooling around."
But passing sentence at the Old Bailey, Judge Mark Dennis QC said the defendant knew Boular was serious and did nothing to alert authorities or put her off.
He also noted Barghouthi's interest in extremist material, although it was a "comparatively small amount".
Mother also jailed
Last Friday, Boular was jailed for life with a minimum term of 16 years, having previously admitted preparing acts of terrorism. Her mother, Mina Dich, 44 was jailed for six years and nine months with an additional five years on licence for helping her.
The court heard that Boular took up the mantle from her younger sister, Safaa, who had planned to attack the British Museum after her Islamic State fiance was killed in Syria. Safaa, 18, will be sentenced at a later date after being found guilty of preparing terrorism in the UK and Syria.
Deputy Assistant Commissioner Dean Haydon from the Metropolitan Police 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."