When Natasha Papworth was weighing up school options for her daughter, Grace, she had one overriding desire for her youngest child, who has grown up with three brothers.
"I want Grace to be a strong, confident woman and we want her to be empowered to make bold decisions," Mrs Papworth, a senior executive in the corporate world, said.
Grace, 14, is in year 9 at Ravenswood School for Girls on the north shore. Mrs Papworth, whose three sons also attended all-boys schools, said there was a "really strong sisterhood" at Ravenswood.
"Grace has a great peer group who are really supportive of each other and the girls don't need to be self-conscious and worrying about their questions in class being silly just because there are boys sitting there," she said.
Single-sex versus co-educational schooling has long been a hotly debated topic between educators, academics and parents.
Supporters of single-sex education point to new research from the University College London, which found converting schools from single-sex to co-ed resulted in falling academic results for both boys and girls.
Led by Christian Dustmann, a professor of economics, the research paper titled Why single-schools are more successful? looked at the experience of South Korea, which converted some single-sex schools to co-ed schools over several years.
Some Seoul schools converted to mixed-sex in the 1990s because of a government policy which favoured co-education.
"For boys, the disadvantage of co-ed schooling is largely due to exposure to a school-level co-ed environment," the paper said.
"For girls, however, it is classroom-level exposure to mixed-gender (versus same-sex) peers that explains the disadvantage from co-ed schooling."
Research released earlier this month said figures from the Australian Bureau of Statistics show the popularity of single-sex schools in Australia is declining, and if the trend continues, there will be no single-sex independent schools in 2035.
Last year, The Armidale School began enrolling girls after 123 years as a boys' school and Barker College, in Sydney's north, is moving from a boys' school to fully co-educational by 2022.
The paper, published by the Australian Council for Educational Research, found students at co-ed schools learn at the same speed as, and sometimes faster than, their peers at boys' and girls' schools.
It found that while single-sex schools have no advantage when it comes to students' academic growth- which is the value added by schools over time, they outperform co-ed schools in overall achievement.
Loren Bridge, the executive Officer of the Alliance of Girls' Schools Australasia, said the UCL research "proves without doubt that girls and boys do better in single-sex environments".
"The study found that girls are more disadvantaged in co-ed classes because of factors such as boys' disruptive behaviour or a teacher's attention being diverted to boys," Ms Bridge said.
"But boys are also disadvantaged, contrary to commonly held belief that boys do better in co-ed environment, boys' academic performance also suffers in a co-ed environment."
But Chris Presland, the president of NSW Secondary Principals' Council, said the "concept of single gender schools can be restrictive for kids".
"Comprehensive education helps to equip students to cope well in a diverse, multicultural world," Mr Presland said.
Queensland University of Technology education academic, Rebecca English, who specialises in school choice, said academic performance was not vastly different between single-sex and co-ed schools.
"The research says there is very little difference in terms of academic outcomes," Dr English said.