Education and Training Act 2020, s 103(c), and s 10 (“parent” definition)
The principal has to tell you about things that are:
preventing or slowing your child’ progress through school, or
are harming their relationships with teachers or other students.
Both parents (or guardians) must be told, even if you are not living together.
You are unlikely to be contacted for minor things like your child talking in class or being late one time, but if the problem keeps occurring you should be told.
Schools, including the board, must follow the rules in the Privacy Act 2020 about handling information. Each school must also appoint a privacy officer, to deal with information requests and generally encourage the school to comply with the privacy laws.