Generally, the public were also much more aware of abuse and reporting incidents, Mrs Sullivan said.
"Family violence is predominant in most of the cases we deal with. There are some adults who do expose their children to violence," she said.
The results could be devastating for children who saw violence, especially psychologically.
"There is a risk of children being traumatised," she said.
"The environment involves a high level of anxiety for them. They see violence as a normal way of getting what they want and a way to express emotions by the very people who they should feel safe around. It can be confusing for them."
It was important for families to recognise violence in order to change things, Mrs Sullivan said. Removing children was a last resort.
"We rarely remove children. It's an absolute last resort. We work with the families so they can understand and recognise that violence isn't okay ... We support them to do that and how to manage conflict in a different way, a healthier way."
In most cases there were underlying issues such as drug or alcohol abuse or financial stresses, Mrs Sullivan said.
Families were referred for extra help with budgeting, counselling and/or Work and Income.
"When there are multiple stresses or a number of children involved, people can become overwhelmed," Mrs Sullivan said.
"Some parents have limited skills to cope with the children and financial stresses. We walk alongside them to make changes for the children. We support the family in accessing services in the community."
Dealing with such cases on a daily basis could be difficult for frontline staff, Mrs Sullivan said.
"It's a difficult job knowing children are living in stressful situations. Mostly, they get a good outcome for the child within the family. They support families to resolve their problems successfully."
If a satisfactory outcome could not be reached, social workers had to prove to judges the child or children were at risk of harm before they could remove them from their family.
"We look to the families to try and find alternatives to ensure the safety of the child," Mrs Sullivan said.
"It can be traumatising to uplift a child. We take action that causes as little distress for the child as possible."
Ministry of Social Development chief executive Peter Hughes said every notification of alleged neglect or abuse was treated seriously, with action taken to ensure the safety of the child or children involved.
There had been a steady increase in notifications in recent years which reflected increased community awareness, Mr Hughes said.
More than one notification could be received for one child.