Film shines light on Obama's Kenyan sister- By Catriona Davies, CNN

When Barack Obama won the U.S. election four years ago, his Kenyan half sister Auma was with her family at their homestead, watching the historic occasion on television.

It was a night Auma Obama remembers well. "We had a lot of people visiting to watch with us," she says. "There was a lot of excitement because it had been such a tough race. There was a sense of relief that all the hard work had paid off."

Alongside Auma and her family was filmmaker Branwen Okpako, who was making a documentary about Auma, "The Education of Auma Obama, " which is being shown in London Tuesday to coincide with the U.S. election and as part of the Film Africa festival.

"I will never forget that period in their homestead," says Okpako. "It was indescribable. Imagine something like that is happening to your family, yet so far away."

Okpako, 43, a Nigerian-born filmmaker living in Germany, became friends with Auma when they were both film students in Berlin in the early 1990s.

"We were two of four African women studying at the film school at the time and we talked a lot about how the African continent was portrayed in film and how we wanted to change it," says Okpako.

Auma shares a father -- Barack Senior -- with her younger half brother, Barack. The pair did not meet until after their father died in 1982 and Barack got in touch with Auma to explore his Kenyan roots.

Okpako had the idea for a film about her friend Auma in the run-up to the 2008 election.

Auma recalls: "I wasn't particularly enthusiastic when Branwen first suggested the film, but I agreed because she is a friend and I trusted her. If it had been a stranger, I don't think I would have done it."

Okpako says Auma was initially reticent about the film because of the huge media interest in her family that came with Barack Obama's rise to prominence.

"It has put me in the limelight in a way that wouldn't have happened otherwise," says Auma. "I don't like talking about my family but it's great if it gives me the chance to talk about my work with deprived and underprivileged children."

Auma, who lives in Nairobi, traveled with Okpako to the family's homestead in the village of Kogelo, where her grandmother lives and Barack Senior is buried.

"We were sitting together for 10 days waiting for the election and reflecting how we got to this moment in time," says Okpako.

"We were reading the newspapers and reading the statistics, but of course we didn't know what was going to happen. It was intense and full of anticipation.

"The film deals with that moment in time when history was made, but also how they got to that moment."

She adds: "All the family was there, the grandmother, all the cousins. Once the result was known everybody in the village came into the compound to celebrate. There must have been hundreds of people there."