'Soon after we married, my husband was killed during the war," says Hawa Abdul-Gadr. Her eyes show a flicker of grief, but her demeanour is purposeful. That said, there is a perceptible sadness – long-suppressed but perhaps closer to the surface than she would care to admit.

Eschewing outward self-pity or sentimentality, she chops her left hand down from her cheek, as if swatting away an invisible spectre. "I am happy now here, we have peace and I hope it stays."

Hawa spent 11 years in a refugee camp in Ethiopia. The border is just 50 miles away from this village in southern Blue Nile state, but for those long years, home here in Kyeli seemed like a distant dream. "I came back in 2006, after the word spread about peace in the camps."

Blue Nile is technically part of northern Sudan, but is de facto split between those who identify more closely with the southern third of the country that has just finished voting on independence, and those who want to remain part of the state of Sudan as it is now. It marks the often indeterminate borderland where Arabic, Islamic northern Sudan meets the African, Christian or animist south.

However, many Muslims in the southern part of Blue Nile identify more closely with southern Sudan than they do with the mostly Muslim north.

Farah Mohamed works for Goal, which runs education, health, water and sanitation projects in Blue Nile, one of the smallest of Sudan's 26 states but which by itself is larger than Denmark. Sitting under a roadside baobab tree in Kyeli, as local men lounge in the shade, sipping espresso-sized coffees away from the afternoon sun, he says: "I am a Christian from the west, but have an Arabic name. It is common here."

On the road, children run home from school, their white uniforms beiged by the brown dust raised by a light breeze. "Khawaja, khawaja [Arabic for 'foreigner']," they shout, pointing and laughing. Women fetch water, five-gallon drums perched atop their heads with an effortlessness belying the load involved. Or they carry firewood, tied in a pair of torso-sized bundles and hung off both ends of a carrying-stick draped across their shoulders.

Hawa also works for Goal, as a trainer in the Reflect programme, offering local women Arabic literacy and numeracy, as well as training on health and hygiene issues. "There is almost no education in this region, apart from a couple of schools," she says. "Most people cannot even read the labels when they go to the market. Part of that is down to the war."

The multiple tribes in the region all speak Arabic as a lingua franca, thought Farah Mohamed concedes that it is often "not proper Arabic", but a pidgin of Arabic and local languages.

Sitting next to Hawa is Sawra Babakr, a 26-year-old mother of three. She is one of Hawa's students in the class, which meets for two hours, five days a week. "I left school at seven," she says. "Before starting Reflect, I could not read or write. Now I at least can read from the board in front of the class."

Two million people died and at least four million others were driven from their homes as the Sudanese army fought the southern-based Sudan People's Liberation Army/Movement (SPLA/M) from 1983 to 2005.

Khartoum sought to impose sharia law on the multiethnic country, soon after it became apparent that the north-south border area was rich in oil.

Blue Nile was one of the worst-hit areas, as the northern army and local militias fought the SPLA/M.

The 2005 peace agreement promised independence for the south, and last Sunday in Juba, the south's capital, I watched long queues form outside polling stations well before the 8am start.

Waiting to enter the station at the tomb of Dr John Garang, the former head of the SPLA/M – a southern hero who ironically wanted the south to remain part of a united, secular Sudan – Bobby Amun, a mechanic aged 22, said: "We are so happy today because we will aim for our independence."

By Wednesday, the turnout in the week-long vote passed the 60% validity threshold, and by all accounts southern Sudanese were set to easily surpass the simple majority in favour of independence.

In Kurmuk, a sleepy market town of 20,000 people and host to a United Nations peacekeeper base, there is a polling station.

However, the place has been almost empty all week, as most people cross into neighbouring Upper Nile state, technically part of southern Sudan, to vote there, amid whispers that the Blue Nile vote might be rigged against a pro-independence outcome.

Blue Nile itself will remain part of the north, but has been granted a 'popular consultation' – a compromise aimed at ultimately giving the region, along with Southern Kordofan, an oil-rich area bordering Darfur, some measure of local autonomy.

With dozens killed there in the week since the referendum started, Abyei – a small region straddling Unity State in southern Sudan and Southern Kordofan in the north – remains volatile.

Both sides want Abyei, through which the main pipeline taking southern oil to northern refineries and ports runs.

Local Arab herders known as the Misseriya and southern-leaning farmers known as the Ngok Dinka fight over grazing rights and land – though it is believed that the powers-that-be in the north and the south arm both sides.

The Dinka is the largest ethnic group in the south, and along with the Nuer, dominates the regional Government of South Sudan (GoSS), which will govern the independent state, if and when that comes about.

Blue Nile is mostly quiet, for now. Whether it remains so may depend on how the economic needs of the people are addressed.

In Kyeli there is no electricity, no running water, no schools. People grow sorghum, beans and vegetables, while herders move goats and cattle along and across the region's winding dirt roads, a bone-jarring two-hour drive from Kurmuk.

Four hours to the north is Sudan's largest hydropower station, at the Roseires dam on the Blue Nile.

The facility powers much of the north, home to oil refineries, large-scale commercial farms and the harvesting of a key ingredient in Coca-Cola and other soft drinks – gum arabic – of which Sudan is the world's largest source.

Part of the reason people in Blue Nile aligned with the south during the war was down to grinding poverty and indifference to their plight shown by Khartoum. "There are no good roads here," laments Sarwa Babakr, while another Reflect student, 30-year-old Zainab Malik, a mother of four who never attended school, says: "People have no money, no future other than to stay on the farm."

Such needs will need to be addressed in the near future, if the region is to remain as calm as it has been in the half-decade since the peace deal. Independence for the nearby south could change the feeling on the ground, and, according to a report by the United States Institute for Peace (USIP), a mismanaged popular consultation "could destabilise not just Southern Kordofan and Blue Nile, but all of Sudan".