"There wasn't a friendly atmosphere between the teachers and support staff at all," she said. "But I'm loud and assertive and said, 'Sorry, you can't kick me out.'"
Now, 18 years later, their relationship is different. "There is a sense now that we are one staff," she said. "We are very friendly and share the same staffroom."
Mrs Stevens has found her job has changed a lot over the years. She started out washing paint pots, sorting out craft equipment and photocopying. Now, for just pound;8 an hour, she also takes groups of children out of class to deliver work prepared by the teacher, and is expected to adapt activities if they are not working well.
She and class teacher Sharon Lynn brainstorm ideas together and work more as a team. Miss Lynn said: "She is expected to take the initiative more. Schools have to be careful they do not cross the line into doing work they are not trained or paid for, but that doesn't happen here.
"She complements me well. I am from a science and maths background and she is more artistic."
Miss Lynn has spoken out in support of her assistant, who will strike on July 16, when the school will close.
Support staff have agreed to come in on July 17 to help take a school trip to London. Miss Lynn said: "I'm an NUT member and went on strike in April. No one takes it lightly. I'm not sure if they will get the result they are hoping for, but there will be more people striking, so they could have some effect."
Photograph: Neil Turner.