But for Grace Halphen, 15, a class assignment on the trials and tribulations experienced by 13-year-olds marks her entry into the world of published authors.

A year 9 student at Caulfield Grammar School, Grace has edited a book of letters penned by famous Australians to their 13-year-old selves.

Letters to my 13-year-old self, which will be published by Affirm Press next year, features words of wisdom, reflections and advice from more than 40 Australian luminaries including Adam Gilchrist, Kate Ceberano, Nathan Buckley, Chris Judd, Judith Lucy and Maggie Beer.

"Starting at a new school was really hard for me. I found it really hard to fit in and make friends … and I am still finding it a bit hard even today," Grace said.

"Turning something that was hard for me into something that can help other people and that will eventually help other people is really nice to know."

The book began life as an assignment known as the Choice Journey in which students are required to follow a topic of their choice throughout the school year and reflect on their learning through journal entries, photographs and an essay.

Grace said she was inspired by the book Bully For Them, by Fiona Scott-Norman, which features 22 entries from famous Australians on being bullied at school.

"What inspired me about them was that they went on to have such successful careers even though school was really tough," she said.

Scott-Norman, who has written one of the entries for Grace's book, was instrumental in securing a publishing deal for the teenager, pitching the idea to her publisher Affirm Press without the young writer's knowledge.

Grace said the issue of bullying featured in many of the contributors' letters and she hoped her book would also be of assistance to young people going through similar experiences.

An aspiring musician who sings and plays violin and drums, Grace says letters sourced from successful Australian musical artists Missy Higgins and Chet Faker were highlights of the project.

"They are people that I most look up to because I also love music and when I was going through a hard time Missy Higgins' music was really helpful."

Singer Kate Ceberano says being 13 was "bloody awful".

"I was overwhelmed. I guess that's the only adjective that describes that age," she says.

"I wanted to be loved by everyone and was mortally wounded if someone didn't love me."

Ceberano was keen to be involved in the project and was struck by Grace's authenticity and entrepreneurial spirit.

"I think it is very exciting when you read something at that age and it relates to you. I think it's important," she says.

Proceeds of book sales will be donated to The Reach Foundation, which aims to improve the wellbeing of young people.

Grace needs another 10 entries to complete the book, which also features contributions from Natasha Stott Despoja, Stephanie Rice, Richard Frankland​, Layne Beachley​, Josh Frydenberg​, Matt Tilley, Jackie French, Kevan Gosper​, David Koch and Jobe Watson.