As well as regular curriculum studies, St Cuthbert's 1350 students also take classes in "thinking skills" and advanced technology.
And studies show girls do better educationally in single sex schools, she says.
"The commitment of our staff to teaching and to their students is another important factor in the students' success," she says.
"We are certainly pleased with this year's results."
But Mrs Reid also points out her teachers are paid more than regular state-school teachers, and they can be, because parents pay around $9000 a year in fees for each daughters at the acclaimed school.
Teachers in state schools are holding unofficial strikes in Auckland and Canterbury to support claims for more pay and more time to prepare lessons.
The teacher-to-student ratio is also better - classes of between 15 and 18 students are the norm.
In the Herald's circulation area, almost all schools with top bursary results were in decile 10, or high socio-economic areas.
The Senior College of New Zealand and the New Zealand International College, which charge almost $11,000 and almost $14,000 a year respectively, continued strong showings.
Of the top 20 schools, only four were not in decile 10 areas - Te Aroha College in the Waikato (decile 6), Hauraki Plains College in Ngatea (decile 4), Mt Roskill Grammar (decile 4) and Hamilton's culturally diverse Fairfield College (decile 3).
Only 15 per cent of Te Aroha College's bursaries in 2000 were As, but last year was a "vintage year", says principal Dave Douglas.
The bursary count increased to 50 per cent of all exams taken.
"If you have responsive kids and a stable teaching staff you are bound to get results," Mr Douglas told the Herald.
"The kids have to do it themselves though.
"At the end of the day you can't ride their horse home for them."
But there has long been controversy about the value of judging a school by how many A bursary scholars it turns out.
John Minto, senior vice-chairman of the Quality Public Education Coalition, says they are a questionable source of information.
"They are misleading, because most top schools have been picky about the kids they choose, and those they won't.
"They can pick and choose and so they choose the high achievers and ordinary kids are left on the sidelines.
"I've some appalling comments about 'ghetto schools' from people who take the league tables at face value, but there is no reason to believe that decile 1 schools, which often have much bigger challenges to start with, do not add as much, or more, to a child through the education they provide."
Bursary exam results - other selected areas
