Brothers Wiremu Curtis, 19, and Michael Curtis, 22, today received life sentences with minimum non-parole periods of 17.5 years for Nia's murder.
Her mother, Lisa Kuka, 35, was sentenced to nine years imprisonment on two manslaughter charges.
Oriwa Kemp, 18, was sentenced to three years, four months imprisonment and Michael Pearson received three years for their ill treatment of the toddler.
Justice in this case has been seen to be done but what about the thousands of other children like Nia who suffer dreadful abuse at the hands of their families in New Zealand?
Who is going to be reponsible for making sure that there is zero tolerance for any form of child abuse in Aotearora.
UNCIEF Report Ranks NZ as amongst worst in OECD for child abuse
A 2003 UNICEF report showed that New Zealand has one of the highest rates of child death from maltreatment (physical abuse and neglect) among rich OECD countries.
It ranked 25th on a league table of 27 countries with 1.2 deaths per 100,000 children