After 15 years as deputy principal, this year she has been given the chance to take the helm and put her ''own stamp'' on the school.
Mrs Harrison was deputy principal of the school from 2002 until the end of last year.
She said the school environment had completely changed since she started there, due to school zoning and Cromwell's significant population growth.
In 2002, the roll was fewer than 70. Now it was about 260.
''I'd come from St Clair School [in Dunedin] where there were 450 kids. I was on duty on the first lunchtime and I was standing out there in the playground going 'I don't know where any of the kids are', because it's huge grounds and 70 kids.
''Now there's four different games being played on the courts and the fields and it's everywhere, so kids are easy to find.
''In [my] first year in 2002, we had about 12 new entrant children and the following year we had about 40.''
Mrs Harrison started her career as a teacher in Dunedin at schools in Mornington and St Clair, with a stint as a lecturer in maths at the Dunedin College of Education. She moved to Cromwell in 2002 to take up the role of deputy principal.
This year, she replaces retiring principal Sharon Booth.
She admitted the school was in a poor shape when she arrived but with the right principal it developed into a school with a positive environment.
''I'm really lucky I get to take over a school that's ticking along nicely ... we're a school in good heart.''
''We've got a building project just about to happen; two new classrooms being built by the end of the year.''
Mrs Harrison is busy outside her job as she is a member of the Cromwell Community Board.
But it is all in support of her home town which she wants to see thrive.
''The freedoms that it gave my family as my kids grew up was the reason for coming here. It's the sort of lifestyle that you can build for your family.''
