As a wizened old woman hacked between her legs with a rusty blade, the little girl screamed out repeatedly for her "mummy" - the person she loved and trusted most in the world.
But her mother turned away. From that day on she never called her "mummy" again.
Like all girls in Somalia who undergo FGM, Wardere was told never to speak about what had happened. But 40 years on, she is determined to break the secrecy that she said perpetuates this "barbaric and medieval abuse".
This week sees the publication of her memoir "Cut", the first book about FGM in Britain where Wardere has lived since fleeing civil war in Somalia as a teenager.
"I felt as if someone had dropped me into bright orange molten lava," she wrote, recalling the day she was cut. "From head to toe the pain burned ... exploding in my brain ... every nerve ending screaming in agony."
But worse was the complete sense of betrayal by her mother. "My life changed forever," Wardere told the Thomson Reuters Foundation. "It severed the closeness, the bond, the trust - everything was gone."
Wardere, a mother of seven from northeast London, is part of a growing anti-FGM campaign in Britain, where an estimated 137,000 women and girls are believed to have been cut and 60,000 girls are thought to be at risk.
She works for a new government-led FGM prevention programme, talking to teachers, school children, medical staff and the police. Her message is simple: FGM is child abuse and everyone has a duty to end it.
FGM nearly cost Wardere her life and she remembers many girls who never reappeared from their huts.
Yet the practice remains almost universal in Somalia where parents see it as an important purification rite designed to protect a girl's virginity.
Many also believe the ritual, called gudnin in Somalia, is a religious duty even though it predates Islam and is not mentioned in the Koran.
In most cases the cutter removes the girls' external genitalia and then sews up the opening, sometimes with a thorn.
"What remains ... can only be described as looking like what's between the legs of a Barbie doll. It is ... a complete denial of womanhood," she wrote.
FGM often causes a lifetime of physical, psychological and sexual problems. Urination can take 15 minutes, menstruation is agonising, chronic infections are common. Later in life, FGM can lead to serious and even fatal childbirth injuries.
The book relates how Wardere's cousin was cut open on her wedding night to consummate the marriage. Many young women begin married life in hospital, she said.
Wardere has suffered nightmares and flashbacks throughout her life.
As she gave birth to her first son, the images in her mind were not of her baby about to be born, but of the cutter and her bag of rusty razors.
"I was an absolute emotional wreck. I was crying non-stop. My husband kept saying: 'Look at the baby, hug the baby'. But every part of me was in pain and remembering my mutilation," she said.
"You feel like you are being ripped apart again. You don't associate anything good with that part of your body. It was horrific."
Wardere met her husband soon after arriving in London and she said they have a strong and devoted marriage, but intimacy has been fraught with difficulties.
She said it is not uncommon for men to cheat on or divorce their wives because they do not have a fulfilling sex life.
It is a cruel irony, she said, that girls are cut to "preserve" them for their husbands yet the damage done may cause their husbands to abandon them.
Shortly before her death, Wardere's mother asked her daughter to forgive her. But her belief in FGM was so entrenched that she still did not understand why Wardere would never cut her own daughters.
GIRLS CUT IN UK
In Britain, FGM is practised by communities originating from countries including Somalia, Nigeria, Eritrea, Sudan and Sierra Leone.
Among Somalis, Wardere believes 60 percent of women of her generation are still cutting their daughters because of pressure from their families and wider community.
Wardere said FGM often happens during the summer holidays - "the cutting season" - so that girls have time to recover before school starts again.
Many are taken abroad to their parents' home countries, but it is widely believed that cutters are also flown into Britain.
FGM has been illegal in Britain since 1985 but for decades the authorities turned a blind eye. However, Wardere said there has been a massive change in attitude.
In the last few years the government has introduced initiatives to identify and protect girls at risk, help women already living with FGM and improve specialist maternity care. It is also funding programmes to eradicate FGM in Africa.
"I think the world is waking up now," Wardere said. (Editing by Alex Whiting; Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, which covers humanitarian news, women's rights, trafficking, corruption and climate change.