A former private schoolgirl who fled to Syria to marry an Islamic State fighter has written an online guide for widows causing speculation that her husband has been killed.

Aqsa Mahmood, who had previously attended Craigholme School in Pollokshields, Glasgow, has criticised wives of extremist fighters for being ignorant of what is expected of them when their husbands die in combat.

Posting under the name Umm Layth, the former private schoolgirl, advised fellow jihadist brides to know how long they needed to wait before remarrying and to learn the proper dress etiquette for widows.

She wrote: "Most importantly know your rights as a Muslimah (single muslim woman. Don't live in ignorance ukhti [my sister]."

She also criticises jihadists for failing to explain to their wives what will happen to them after they die.

Mahmood, who is in her early 20s, previously wrote on the social networking site Twitter under the same name.

The Twitter account was set up in August 2013 but disappeared in September 2014 when her name was linked to Islamic State.

In September 2014 she stated that she would only return to the UK if it was flying the flag of the Islamic State.

Her comments at the time were in response to David Cameron stating that suspected British-born jihadists returning from Syria and Iraq could face losing their passports.

After disappointing results in her Highers, Mahmood moved from her private girls' school to Shawlands Academy and then on to Glasgow Caledonian University where she was studying for a degree in diagnostic radiography before she dropped out and left for Syria in November 2013.

She is believed to have travelled to Aleppo where she married a Sunni extremist.

Mahmood, of Pollokshields, Glasgow, has one older brother and two younger sisters.

She was described by her parents Khalida and Muzaffar Mahmood, who are horrified at her activities, as a "bedroom radical".

Speaking in September last year, they spoke of their shame at what she had done and begged her to return saying: "We still love you but we now have to put your family, your brother and sisters first as you have betrayed us, our community and the people of Scotland when you took this step."