When she refused to consumate the marriage, her husband invited two of his brothers and a male cousin to help him rape her, the rights group said. "One held her chest and head, the others held her legs", Al-Imam told the news outlet.
The family handed her over to the police.
A Sharia court, which follows Islamic religious law, found Hussein guilty of premeditated murder last month and on Thursday officially sentenced her to death by hanging.
"Criminalisation of Noura for defending herself from assault and, in particular a death sentence, would violate her rights under the Sudanese Constitution and global law".
"The next morning he tried to rape her again but she managed to escape to the kitchen where she grabbed a knife".
Girl's lawyer told reporters that the father Nura persuaded her to return home, but as soon as she returned home, it was immediately handed over to the legal wife. She said that while the rape and harassment of women had always been an issue in Sudan, a case like Hussein's had never gone viral. Across social media, Sudanese activists and supporters in Europe, Australia and Washington have rallied around Hussein. The man's family Nury requires that the death sentence was carried out. Forced child marriage and marital rape are not considered crimes in Sudan, and can not be used as evidence in a defence.
Randa Elzein tweeted "I was never sadder and more shaken than when i saw Noura today".
The judge asked the deceased man's family which option they wanted, and the family chose execution. Thousands of people have shared a change.org petition. "Marital rape happens in Sudan often and people don't talk about it", he said. "She stood for her rights".
Sudan is ranked 165 out of 188 countries on the U.N.'s Gender Inequality Index, which measures how women fare compared to men when it comes to access to health, education, political participation and employment opportunities.
Magango, of Amnesty International, said that by applying the "cruel" death penalty to a rape victim, Sudanese authorities failed to acknowledge the violence Hussein endured.