A mental health panel in South Africa unanimously decided that the 34-year-old businessman, from Bristol, is not mentally ill and should be tried in October for Anni Dewani's murder in Cape Town.
Her sister Ami Denborg said: "It's a relief for all of us. We've been waiting quite a long time for this. I know this autumn is going to be tough for us but we still want the trial to start so that we can get the information we need, we can get to know what really happened.
"It feels like we're moving forward. It's still a long way to go but at least we're taking steps in the right direction, and this feels like a huge step in the right direction."
Director of public prosecutions Rodney de Kock told the Western Cape High Court yesterday: "The accused is not mentally ill. The accused is not certifiable in terms of the Mental Health Act."
Dewani's lawyer Francois van Zyl said there was no objection.
He will be held at Valkenberg Hospital in Cape Town, as agreed under the terms of his extradition from the UK, until his next appearance for a pre-trial hearing on September 9, before his trial starts on October 6.
The millionaire is accused of ordering Anni's murder during their honeymoon in November 2010. She was shot in the neck as the couple travelled in a taxi on the outskirts of Cape Town.
Dewani, who has not yet entered pleas, faces charges of conspiracy to commit kidnapping, robbery with aggravating circumstances, murder, kidnapping, and defeating the ends of justice.
Three men have been convicted and jailed over Mrs Dewani's death, including taxi driver Zola Tongo, who was given 18 years after admitting his role in the killing. Xolile Mngeni, who prosecutors claim was the hitman, was convicted of premeditated murder over the shooting, and another accomplice, Mziwamadoda Qwabe, pleaded guilty to murder and was given a 25-year prison sentence.