The event was organised by the Whanganui branch of the New Zealand Educational Institute (NZEI) and all support staff in Whanganui were invited to attend.
Nimmo said that those in attendance were made to feel valued.
"We are reassured by teachers and principals that schools would not manage without support staff," she said.
"Support staff cover administrators, teachers aids, librarians, science, technology and all sorts of other things."
In her role, Nimmo sits beside children and supports them with any number of their core subjects from writing and reading to science and maths.
"It means that I am supporting some of the most vulnerable children in our society, I empathise with them, I support them and I enable them," she said.
"We are very dedicated and we give a lot of ourselves to our roles."
Nimmo is part of the NZEI support staff national leadership group and has been involved in support staff for more than 30 years.
"Most schools were represented on Wednesday, most try to send all of their support staff along, I haven't seen the final figures, but we packed out Caroline's and it was lovely," she said.
"There was the most glorious food that appeared on the tables, it was a matter of sitting beside your colleagues, talking about our roles, new ideas and enjoying friendship."