The teenager used the video chat system to wed Naweed Hussain, a Briton who had travelled to Syria to join up with jihadis.
Together they allegedly planned an atrocity in which she would use hand grenades and a pistol to kill innocent civilians.
In court yesterday, she strolled into the dock wearing a navy Nike tracksuit, with her long hair swept back in a high ponytail.
The teenager, who is said to have wanted to ‘become a martyr’, is thought to be the youngest British woman to be charged with planning a terrorist attack on UK soil.
Westminster Magistrates Court heard how the youngster was 16 when she hatched a murderous plot with Hussain.
It was claimed that he had earlier tried to radicalise a former Sun Page 3 girl as he hunted on Facebook for a bride to join him in Syria.
Prosecutors believe he later got in contact with the 17-year-old girl, who was said to be ‘self-radicalised’.
Police stopped her travelling to Syria to be with him in August last year and the pair married over Skype weeks later.
When the jihadi, who calls himself Abu Usamah al-Britani, was later killed in fierce fighting in the IS stronghold of Raqqa, his young bride is alleged to have taken charge of their plot from the £1million home in London where she lived with her family.
She is accused of arranging for hand grenades – which she dubbed ‘pineapples’ – and a Russian semi-automatic Tokarev pistol to be brought into Britain for the attack which is thought to have been planned for a British museum.
The 17-year-old, who cannot be named for legal reasons, was on bail at the time after being charged in April this year with planning to travel to Syria.
The 17-year-old appeared in the dock at Westminster Magistrates’ Court (file picture) yesterday
The court heard that after being released by police she continued to chat to others about a gun attack and was given instructions on how to train and operate the weapons.
She is also accused of trying to enlist others to carry out the museum plot.
Prosecutor Karen Jones said: ‘She was arrested … for being involved in attack planning in the UK which occurred while she has been on bail in relation to these matters.
‘The allegation is that having had her plans to travel to Syria thwarted in August 2016 she continued to engage with Naweed Hussain, a Daesh fighter resident in Raqqa who she married in September on Skype.
‘Between them they hatched a plan to conduct an attack in the United Kingdom. They then engaged with others and indicated exactly what that plan was.
‘She was effectively going to receive pineapples, otherwise known as hand grenades, and a Tokarev firearm, and she intended to carry out a terrorist attack in the UK… she having a desire to become a martyr.’
As the youngster appeared in court yesterday she dressed like a typical British teenager, biting her lip as she stood in the dock with her hands stuffed in the pockets of her casual Nike tracksuit as prosecutors laid out the case.
She spoke only to confirm her name and her solicitor Vajahat Sharif said on her behalf that she would be pleading not guilty to charges of intending to commit acts of terrorism between December 1 last year and April 12 this year.
The girl was charged after a probe by the Metropolitan Police’s Counter Terrorism Command
District Judge Tan Ikram remanded her in custody to appear at the Old Bailey on August 11.
At a previous hearing at the Old Bailey in April for the earlier charge of planning to travel to Syria, the young woman cut an altogether different figure when she wore a burka, with just her eyes visible.
Last year it was reported that Hussain had been brazenly using social media to groom a new generation of jihadi brides from Britain and the West.
In March this year his brother Nadeem was jailed for four years at Kingston Crown Court for sending the jihadi £4,000 in Syria.
It emerged for the first time yesterday that IS recruiter Hussain had recently been killed in Syria. It is not known how he died.
His 17-year-old bride is unlikely to have ever met her husband as he has been in the war-torn country since 2016 unknown to her.