Today, her beaming face is emblazoned across the Union Roasters fair trade coffee packs on sale in supermarkets across the UK. But in person she is slight, languid and rarely smiles.
Staring out at snow flakes falling on Tottenham Ct Rd – the first time she has ever seen London or snow – she huddles under a grey cardigan.
"What happened in the genocide was that we lost hope of life," Gemima whispers in a voice so delicate a gust of wind might break it.
"I personally lost my people and became destitute. But when the co-operative started up, I joined it and started to regain myself.
"Some of the people in our co-op in Maraba were directly affected by the genocide. Others have relatives who carried it out. But because we are working together in a supportive group, our feelings are slowly but surely being healed. We are becoming better citizens, and better Rwandans."
In April 1994, Interahamwe Hutu militias, armed and trained by powerful figures in the West, began an extermination campaign against Rwanda’s minority Tutsi community. Their weapon of choice was the machete.
"One way of marking the 10th anniversary of the genocide would be to face up to our failure. Why didn’t we act? What were our duties under the genocide convention? Did we breach them, and how can we make sure we never do that again?”
former International Development Secretary, UK
There are few visible differences between the two ethnic groups but "Hutu" means "servant" while "Tutsi" means "rich in cattle". Tribal and racial differences were less important than the fact that Tutsis were perceived as relatively privileged.
While the virtual complicity of the French and Belgian governments in the horror has been well documented, Britain is also culpable.
The UK’s former ambassador to the UN, Sir David Hannay, was widely seen as having given the green light to extremist Hutu’s by proposing a 90% reduction in UN forces in the country, as the massacres were starting.
The former International Development Secretary, Clare Short, believes it is time for a full public inquiry to establish the UK's culpability in the events of April 1994.
"There have been inquiries in other countries,"she says. "There was one in France because they were almost complicit. There’s been a massive UN inquiry too, but Britain has never looked at what it did.
"One way of marking the 10th anniversary of the genocide would be to face up to our failure. Why didn’t we act? What were our duties under the genocide convention? Did we breach them, and how can we make sure we never do that again?
The UN abdicated its responsibility
towards the people of Rwanda
"I don’t think it’s a war crime to fail to honour the obligations we have under the Genocide Convention," she adds. "But it is an enormously serious political failure, and there has been a total failure to face up to it."
Patrick Habamenshi, the Rwandan agriculture minister, says that the war crimes tribunal in The Hague should be expanded to consider the role played by particular Western figures outside his country.
"I have a certain number of names in mind but I will not say them now," he says. "I am a strong believer that justice should pursue its course and if the opportunity is given to me, I will go and testify."
"Some people are still in positions where they can prevent things like that from ever happening again. Are they doing everything they can? I’m not sure."
The UN’s under-secretary general in charge of peacekeeping operations in 1994 is one figure who has been criticised for not doing more to stop the horror.
He was warned of the coming genocide three months before the event by Romeo Dallaire, the head of the UN’s peacekeeping force on the ground but chose not to pass on the information. As a result, the UN Security Council did not discuss Rwanda during the first month of the slaughter.
The name of the negligent official is Kofi Annan.
While Habamenshi, like most Rwandans, now talks of the need to move on and look to the future, he is angry that in some quarters there is still a reluctance to accept that genocide took place in Rwanda.
"What I experienced during the genocide is beyond verbal description. I was cut with machetes, beaten, tormented and almost killed"
This may stem partly from a fear of prosecutions at The Hague but partly also, from a desire to avoid legal liability.
"It is outrageous that we should have to beg to get those reparations," Habamenshi says. "It should be natural. The first step is for the world to recognise that genocide took place."
"It is a process and one day people will go through it but it seems that it is slow to come."
Ilde Phonse, the mayor of Maraba, believes that an international fund should be set up to help projects like the Union Roasters co-operative.
"What I experienced during the genocide is beyond verbal description," he says. "I was cut with machetes, beaten, tormented and almost killed." Ilde still bears a deeply gouged scar on his face but he speaks with hope for the future.
"I wish you knew the state of Maraba before the co-operative came. It would help you to understand the impact it has had. It has delivered people from a self-centred and withdrawn state, into a community.
Many Rwandans are still living with
the horrific memories of the events
"It has helped those who are weak to be stronger, and those who are stronger to share their knowledge with others."
One person helped was Pascal, a 23-year-old co-worker of Gemima’s, who lost much of his family in the bloodletting. He survived by hiding in the attic of his family’s house.
"We felt so bad as children," he says. "All of a sudden, our friends would be killed or disappear. They were people we would never see again. I lost my relatives, and was only lucky that my brothers and sisters survived."
Ilde, Gemima and Pascal are all Tutsis but they bridle at questions about their ethnicity. They just want to talk about coffee.
The Abahuzamugambi Bakawa collective on which they work, employs 1500 farmers growing, picking, pulping and washing the coffee cherries that make Maraba Bourbon, a speciality gourmet coffee.
Because no middle men are involved, the farmers receive more than three times the price they would otherwise get, and the profits are shared equally between the farmers.
"We felt so bad as children. All of a sudden, our friends would be killed or disappear. They were people we would never see again. I lost my relatives, and was only lucky that my brothers and sisters survived."
According to Patrick Habamenshi, the co-op has also brought much-needed infrastructure such as schools, hospitals and roads to Maraba for the first time. But the region suffers from terrible poverty, compounded in districts like Maraba by the effects of the genocide.
There are still not enough co-operative jobs to cope with the demand for places and Rwanda’s fair trade experiment has yet to make inroads into the non-gourmet market. But after a decade of anguish, there is at last a seedling of hope.
Back at the Jury’s Inn hotel, where she will meet British dignitaries with Ilde and Pascal, Gemima professes herself satisfied with the Union Roasters coffee packaging of her photograph.
"It is very positive because as an individual I will benefit and members of the cooperative will benefit," she says, too deadpan to be serious, "and the people who buy the coffee, they will benefit too."
And with that, she allows herself the faintest of smiles.