Rolling school closures are the "new normal" during the coronavirus pandemic, the NSW premier says, but a pay freeze for public sector workers - including teachers - is only temporary and "the least-worst option".
Two non-government schools in Sydney's eastern suburbs remain closed for cleaning following positive cases among students.
Waverley College says its senior campus will reopen on Friday after a 12-year-old Year 7 boy tested positive earlier in the week.
Nearby Moriah College said it's planning to re-open next week after a 10-year-old pupil tested positive.
A total of 31 people have been identified as close contacts of the Waverley College student while 54 were close contacts of the Moriah College pupil.
Ms Berejiklian on Wednesday denied jumping the gun in encouraging students to return to classrooms this week.
"This (temporary closures) is the new normal during the pandemic," Ms Berejiklian told the Nine Network.
"It is a very big coincidence two students in close proximity happened to get it when we have had very low numbers of students actually getting the disease.
"Because this happens in two schools with one student each doesn't mean you shut down the entire system."
Public school students returned to full-time classroom learning from Monday.
Almost 3100 cases of COVID-19 have been recorded in NSW with some 465,000 tests carried out across the state.
One person is currently in intensive care and the state's death toll remains at 50.
Ms Berejiklian last week announced a freeze on pay rises for MPs and this week extended it to the entire NSW public sector, comprising almost 410,000 workers, which could save $3 billion.
Unions say the state government's pause on pay rises for teachers, nurses and cops, among countless other workers, is "a slap in the face" and industrial action could be on the cards.
Unions NSW secretary Mark Morey on Wednesday said it was an act of "economic vandalism" at a time when frontline workers were risking their lives.
Ms Berejiklian has guaranteed, however, that no public sector workers will be subject to forced redundancies over the next 12 months - barring senior executives.
She argued that assurance may not have been possible but for the pay freeze.
"It's the least-worst option, let me assure you," the premier said.