“ If I can stop one child being radicalised, that will be the day I will know Martyn hasn’t died for nothing,” Figen Murray says.

Her son, Martyn Hett, was one of the 22 people killed in the 2017 Manchester Arena bombing.

The 29-year-old was among thousands of Ariana Grande fans pouring out of the venue when Isis supporter Salman Abedi blew himself up in the crowd.

A year after the attack, his mother started a mission to stop other young people being drawn down the same path as the terrorist.

She has so far spoken to more than 6,000 secondary school pupils across England, urging them to confront the terrible impact of the Manchester bombing and helping to steel them against the extremism that caused it.

“I really feel that I could just stop that one child who may be going down the road of being radicalised – if they hear my story it might just make them stop,” she tells The Independent.

The 58-year-old has visited schools across England, from Blackpool to Southampton, including the one attended by Abedi himself.

Ms Murray first went to the Burnage Academy for Boys with Mike Haines, the brother of aid worker David Haines who was among the hostages beheaded by Isis in 2014.

“I remember walking into the building through the front door thinking, ‘That’s weird, I’m breathing the same air that he breathed, that’s really strange,’” she says.

But Ms Murray returned to do her own talk, at first speaking to a year group but then going into individual year-9 classes.

As at other schools, Ms Murray told the children about Martyn’s death and the family’s experience, before inviting them to ask questions.

Murray is now studying counterterrorism (ITV)

She says that many children ask why she forgave Abedi and how she copes: “I had one girl say to me, ‘I lost my little sister a few years ago and can you give me hints on how to grieve?’

“I talked to her about maybe keeping a diary, writing her letters. I told her I chat to Martyn all the time. I talk to him a lot, I think about him a lot.”

Children also ask Ms Murray what she would tell her son if she could. She answers: “I’d say, ‘Please don’t go to the concert, stay with me.’”

Martyn was one of the first victims to be identified on social media, and a journalist who went to the family home hours after the bombing told his sister of his death before it was confirmed.

Manchester bombing victim's parents 'not giving in to hatred'

Martyn worked as a writer and PR manager, but had thousands of followers on Twitter and made popular YouTube videos, becoming well-known for his tattoo of Coronation Street’s Deirdre Barlow and a winning appearance on Come Dine With Me.

He made the news in November 2016 after sharing a photo of unsold items knitted by his mother for a craft fair, sparking a deluge of customers for Ms Murray’s online shop.

In his last tweets on 22 May 2017, Martyn documented a day “drinking prosecco and seeing Ariana” before the concert and shared photos with his partner, sending his last joke less than an hour before the blast.

Ms Murray says she started forgiving Abedi for the bombing after seeing a photo of him in a newspaper just three days later.

“I stood for ages looking at it thinking, ‘Oh my good he’s so, so young, what the hell did you do that for?’”

Weeks later, she was reading a newspaper again following the Finsbury Park attack, where a right-wing extremist ploughed a van into Muslims near a London mosque.

On the front cover was a picture of the terrorist, Darren Osborne, surrounded by a human chain of worshippers and an imam who were protecting him from the angry crowd.

“In all that chaos and confusion and terror, these men made a decision to protect this guy,” Ms Murray says.

“They decided what to do in that moment, and I had to decide too.”

She contacted the BBC and appeared on television the following day to publicly forgive Abedi.

Now her aim is to provide a way for children, particularly in Greater Manchester, to discuss the bombing and wider issues around terrorism and bereavement.

Mariah Carey was among those paying tribute to Martyn following the attack (Instagram/Twitter/Martyn Hett)

Ms Murray is hoping to safeguard them against radicalisation, saying that in an average group of 100 teenagers between 60 and 80 put their hands up when asked if they have seen terrorist material online.

“One of my daughters went on Facebook and saw a beheading video years ago,” she says. “The internet targets secondary school children and it is rife.”

Her talk ends with a call for action, where children are asked to write down acts of “random kindness” that they will carry out.

As she continues to tour schools, Ms Murray is also campaigning for increased security at event venues and studying part-time for a master’s degree in counter-terrorism at the University of Central Lancashire.

A video of a terror training exercise gave her a flashback to Martyn’s body, but she is persevering with the course to “understand what terrorism is about”.

“It’s not just what’s happening and how it came about, but what is being done about it,” she says. “The course is helping to give me answers.”

Ms Murray says her four surviving children support her crusade, which has become part of the family’s grieving process.

She jokes that Martyn is “sat on my shoulder giving me earache”.