Posted Twitter picture of her four-year-old son with an AK-47 rifle

Married to an Islamic State extremist in Syria complete with handguns and his' n' hers Kalashnikov rifles, Khadijah Dare's is no ordinary life.

But it is a world away from her previous existence as the Lewisham teenager who wore jeans and platform heels and loved her mother's home cooking.

And hours after the beheading of American journalist James Foley at the hands of a British jihadist, this 22-year-old gloated on social media at his execution and vowed that she would be the first British woman to kill a US soldier.

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Hatred: Khadijah Dare, 22, was born a non-Muslim in south London but has urged others to follow her in jihad

Dare was gleeful that the 'UK must be shaking up' after the execution and from her home in the Syrian scrub she tweeted: 'Any links 4 da execution of da journalist plz. Allahu Akbar. UK must b shaking up haha. I wna b da 1st UK woman 2 kill a UK or US terorrist!'

Dare's Twitter account is already notorious – not least because of the photograph of her then four-year-old son Isa, meaning 'Jesus', holding an AK-47 rifle.

Her Twitter feed is littered with images of dead bodies and Islamic State propaganda, but juxtaposed with these are pictures which belie the normal young girl she once was.

The irony of the images she has posted of 'beautiful' sunsets, baby seals and a kitten in a teacup alongside those of extremist horror are apparently lost on her.

Khadijah Dare – one of her many post-conversion pseudonyms – grew up in Lewisham, south London, as a non-Muslim, and an acquaintance of hers told the Evening Standard that she was 'very endearing and sweet.

Disturbing: A Twitter post showing Dare's four-year-old son grinning as he brandishes an AK-47 rifle

Arranged marriage: She became radicalised online before marrying her Swedish husband Abu Bakr

'She was a bit of a tomboy but sometimes at weddings I'd see her wearing tight jeans and platforms. She also had braces and dimples and was very cute.'

Tomboy Dare liked to watch football on TV as a child, and loved Chinese food and her mother's home cooking.

When she was older she went to a local college to study media studies, film studies, psychology and sociology, and was a popular young girl.

But it was at the age of 18, four years ago, that she converted to Islam and began worshipping at the Lewisham Islamic Centre – which has links to both the Woolwich killers of Lee Rigby and radical cleric Abu Hamza.

She admitted in a Channel 4 report last year that when she began wearing the full face veil in Lewisham people on the street told her to 'go back to her country', to which she replied: 'I was born round the corner'.

In the same footage she urges other Muslims to 'stop being so selfish...focusing on your families or studies' and implores them to join her in Syria and join the holy war.

Horrific: James Foley was brutally murdered by ISIL. Dare disgustingly gloated on social media at his execution

Dare allegedly became radicalised online and moved to Syria in 2012, before marrying her Swedish Muslim jihadist husband Abu Bakr, arranged by his mother.

Bakr is fighter with the Sunni jihadi militia known as Katiba al Muhajireen - the battalion of migrants – which joined forces with Islamic State and wants to create an Islamic caliphate.

The Londoner has admitted that her parents are unaware of her new life, and as well as the pseudonym Khadijah Dare she goes by 'Umm Isa' meaning 'mother of Isa' and Muhajirah fi Sham, meaning 'Immigrant in Syria'.

As her toddler sons Isa and Abdur Rahman stumbled about her gun-littered living room floor last year, Dare was unrepentant of her decision to move to Syria and of her departure from the girl-next-door who traded her promising British life for one of violence and hatred.

Muslims attending Friday prayers at the London mosque where female jihadist Khadijah Dare used to worship today insisted it was not a breeding ground for terrorists.

Today people at the Lewisham Islamic Centre spoke of their shock and horror at what she had said as they left the mosque in south east London.

A woman, in her early twenties wearing a white headscarf who would not give her name, said: 'I know Khadijah. She attended the mosque a couple of years ago.

'She's a very nice girl, a good person, I had no idea she was fighting in Syria. I'm shocked to hear it, it seems so unlike her.'

Another woman said it was impossible to know Khadijah's motivations, but wondered why the media was so interested.

She said: 'My father's a soldier for the British army, yet no-one challenges him when he goes off to fight. Why should it be any different for us?