Prepped, plaited and packed to go ... cousins Demi Bresnahan, Mia Toohey and Jasmine Rose will start school together at Our Lady of Fatima in Caringbah. Photo: Adam Hollingworth

THREE little cousins thought they had a pretty good scam going. They would tell their teachers that they were not related to outwit the adults who were trying to separate them as they started school together.

Angela Bresnahan said she and her two sisters had asked teachers to separate their daughters, who have grown up together.

Mrs Bresnahan - whose daughter Demi, 5, will start kindergarten at Our Lady of Fatima primary school in Caringbah with her two cousins tomorrow - said she discovered the girls had a counter plan.

''We'd asked the teachers to separate the girls,'' she said. ''But the three cousins wanted to tell the school that they weren't cousins so they could be together.''

Thick as thieves, the girls have played and gone to preschool, little athletics and dancing classes together.

''They have been playing dress-ups in their school uniforms,'' she said. ''They are really excited about starting school.''

Gabrielle Rose said she and her sisters all lived in the Caringbah area, not far from their family home in Cronulla.

''I think it's great our three daughters have done everything together,'' she said. ''This is a big event, starting school together.''

Katrina Toohey, whose daughter Mia, 5, has two older brothers at the same school, said she was confident the three would make friends with other children.

The principal, Tony Boyd, said most students would start school today but kindergarten students would start with a half day tomorrow. ''We have had an increase in enrolments this year,'' he said. ''It is the biggest kinder we've had in some years. This year 100 kids are starting; last year it was 87.''

Public school students also return today after teachers went back on Friday in preparation.

The state government is extending its teacher mentor program this year and has spent $5 million at 92 schools.

The program is designed to support beginning teachers, many of whom leave the profession within five years of starting. The schools include Glenwood High, where Richard Schiliro is mentoring three new teachers.

Mr Schiliro, who has taught for 18 years, said the program was introduced in 2003 in response to the high attrition of new teachers: ''It is really important we support the teachers in their first three years of teaching so there are enough teachers in the future.''