An HMIE report into the school in 2003 found "major weaknesses in leadership", poor relationships with staff, little staff teamwork, lack of communication, resistance to change and a falling school roll.
The contrast with the follow-up report in April this year could not have been more startling. Inspectors found "very effective leadership", characterised by "determination and flair", greater teamwork, duties fulfilled with "commitment and enthusiasm", and clear evidence of a positive impact on attainment and school morale.
The improvement is not all down to Mrs Denningberg, as she admits.
Following the early retirement of the then headteacher, North Ayrshire Council put in Christine Quinn, a quality improvement officer, as acting headteacher for six months to build on the support she and Lesley Owens, head of service, had already been giving the school.
There were already a lot of very good staff in place but, Mrs Denningberg says, they were more used to managers, not leaders. New initiatives had been ushered in without explanation. There was no understanding of processes or common goals, so people followed their own agendas.
For the pupils, the work was monotonous and catered to one learning style.
As children moved up into new classes, they would have to change to suit the new teacher's approach. Overall, staff and pupils lacked confidence and a sense of purpose and pride.
The difference that Mrs Denningberg made was the difference between being a leader and a manager. "Leadership is something different," she says.
"Leadership is about a vision - not about mechanics. Leadership means pushing people to their limits and looking for their potential and creating a desire in people to fulfil that potential."
"Leadership is very much more about talking to people; it is also about being outward-looking. You have to be able to see possibilities to fit into where your vision is going and maximise these opportunities. Networking is important so that you know what is going on in the wider world. You can't be a leader and be very introverted, looking only to your own school, because the world is changing so much."
Mrs Denningberg's first task was to build confidence. Then she standardised practices and insisted teachers adapted to suit children, not the other way around. She tried to instil an understanding that each class was accountable to the next. She also cracked down on quality - even seemingly little things about how well photocopying was done and the display of children's work.
The school introduced formalised prize-giving and established annual nativity plays, pantomimes and end of year shows.
Although the Audit Scotland report is examining the effectiveness of leadership development, Mrs Denningberg has not participated in continuing professional development courses such as the Columba 1400 programme, the Scottish Qualification for Headship, or similar initiatives.
Her previous school, however, went through the Investors In People programme, bringing her into contact with the business world. "The qualities of leadership are built long before you go on a leadership course," she says. "All that does is focus you and give you different opportunities for how to get there."
What is also critical, she believes, is having the right backing and infrastructure of support - which, she says, North Ayrshire has given her.