Siwatibau led a group called Concerned Mothers Group Against the Bill in opposition to controversial legislation proposed by the government of Laisenia Qarase in early 2005, to make provision for amnesty to be granted to persons convicted of involvement in the coup of 2000. She said on 16 June 2005 that the widespread opposition to the legislation was motivated not only by its contents, but also because of what she said was the government's unwillingness to proceed with its development in a transparent and consultative process. Opposing amnesty for perpetrators of political crimes, she called instead for more direct compensation of the victims of such crimes. "I do not see why they want to claim for compensation when this could be done through the Ministry of Labour on the workmen's compensation of something like F$20,000," she said. Siwatibau expressed concern that the legislation threatens the independence of the judiciary. She also said she was alarmed that it would have a corrupting effect on the minds and character of the future generation, which would threaten the future stability and prosperity of the nation. Children, she said, should not be exposed to this "coup culture." Reacting to the decision of the Great Council of Chiefs to endorse the bill, Siwatibau said on 29 July that had not been given enough time to deliberate on the matter. Over four fifths of the Great Council members are delegates of the country's fourteen Provincial Councils, which all endorsed the bill - something which came as no surprise to Siwatibau as they had been briefed only by the government and were required to make a decisionon the spot, without being given the opportunity to hear alternative viewpoints. At the very least, she said the Provincial Councils should have been given a Fijian translation of the bill.
A native of Moturiki Island in the Lomaiviti archipelago, Siwatibau was married to the late academic leader and former Vice-Chancellor of the University of the South Pacific, Savenaca Siwatibau, from 1966 till his death in 2003. They had three sons - Simione Ramacake, Ropate Rakula, and Atunaisa Taleasiga - and one daughter, Asenaca Tania Tuivanuavou.
