"These predators are going to find a way through the system anyway," she said.
"If it is children they are targeting, the schools are the place to get into. It's an awful situation."
Principals Federation president Whetu Cormick told Newstalk ZB's Mike Hosking the numbers were disappointing, but a good sign the system was working.
"I think the Education Council has a very good reporting system to enable these matters to be brought before them."
Cormick said there were tight rules around reporting inappropriate teachers.
"The Education Act clearly says that principals, myself included, and trustees need to report this information on to the Teachers Council so that they can discipline these individuals."
Kerr told Newstalk ZB's Rachel Smalley she believed the appropriate checks and balances were in place, as long as schools stuck to them.
"We just have to keep being rigorous about our processes, and we have to have an unrelenting focus on our processes," she said.
The Education Council is working on a new Code of Professional Responsibility for teachers, due in July. It updates its code of ethics.
Manager of teacher practice Andrew Greig said good processes were in place to ensure such behaviour was dealt with.
"Where there are concerns principals, employers at early childcare centres, they report that to us and as soon as they report that to us we carry out an investigation."
Greig said poor behaviour was uncommon in the profession.
"We are disappointed that there are some teachers that have been struck off for that sort of behaviour but in the context of 100,000 teachers it's a very, very tiny percentage."
Greig said the new code will go some way towards stamping that sort of behaviour out completely "to ensure that the 100,000 teachers in New Zealand are very professional and also acting appropriately in front of our students".
One of those stuck off last year was primary school teacher Mark Robert Ashby, 27, who admitted grooming and indecently assaulting a 14-year-old girl.
In April 2015 he picked the girl up in his car and drove a short distance away before putting his hand inside her top.
He also sent the girl thousands of texts and sexually explicit Snapchat videos in September 2015. He was sentenced to 10 months home detention.
At the time of sentencing, the victim's father described Ashby as a "monster" and "scumbag predator" and said he should not be allowed near children.