Asha Devi, Nirbhaya's mother, has said she is "very happy" with the Supreme Court's confirmation of the death sentence for one of the four convicts in the in the 2012 gang-rape, torture and killing of her daughter - a 23-year-old medical student whose gang-rape and murder in Delhi in December 2012 shook the nation. "It is good and we have gone a step closer," she told NDTV minutes after the top court issued its order.