The only child can be smothered by affection, spoilt rotten, or neglected and left alone to dream and ease their isolation with imagined companions and adventures.
The fictional only child is a constant presence in our culture: Pip, Harry Potter, Jane Eyre, Snow White and Hamlet are just some of the famous only-child characters who have taken the rest of us on wild, emotional rides by their side.
Another is Matilda Victoria Adelaide, the heroine of Sonya Hartnett's book The Ghost's Child.
An unusual and isolated child who does not fit in well at boarding school, Maddy, as she is known, is whisked away on a great journey around the world by her father in a quest to find the world's most beautiful thing.
Connected to nature, she talks to the west wind and the birds, but the beautiful thing turns out to be a wild boy named Feather, with whom she falls in love and tries to build a "respectable" life.
Unusually, the story is told from her perspective as an old woman, sitting in her lounge with a visitor and looking back at her life's journey through all the ghosts of those she encountered along the way.
The Ghost's Child was the Children's Book Council of Australia's book of the year in 2008, the same year Hartnett became the first Australian (before Shaun Tan) to win the Astrid Lindgren Memorial Award - the world's most prestigious international prize for children's and young adults' books. Her other works include Thursday's Child, Of a Boy and The Midnight Zoo.
Among those blown away by Hartnett's poetic, evocative writing is WA theatre-maker Sally Richardson, who jumped at the chance to adapt The Ghost's Child into a physical theatre show.
"I read Australian literature quite extensively because I love it and it is very rare that I will read something that I think 'This must go on stage'. This was one of those books."
The strong word pictures that emerge in Hartnett's writing lend themselves to highly theatrical visual storytelling, says Richardson, who has worked on the show for the past 2 1/2 years with the backing of Performing Lines and the Mandurah Performing Arts
Richardson says the story explores the nature of love and loss, what it means to be true to oneself and what it means to live a life well, even when it is not what you thought it would be.
"Really it is about exploring how we are all different and struggle to find our place in the world," she says.
For the past 25 years, Richardson has been making stage works spanning dance, theatre and circus, including The Drover's Wives, H2O, and The Promise, which won the 2009 Helpmann Award for best children's production. For The Ghost's Child, she draws on a wide range of talent, including Nicola Bartlett and Katya Shevtsov as the older/younger Maddy, and former Sydney Dance Company dancer Kynan Hughes.
Musician Melanie Robinson will perform the cello live on stage as part of a soundscape that features the cries of sea eagles and her own looped voice.
Inspired by the illusory physical theatre-circus traditions of such recent Perth Festival hits as Raoul and Donka, everything on stage will transform into something else: objects will pop out of suitcases and fly through the air, walls will become giant sails and shadows will take on life of their own.
"I think that's what people want to see when they go to the theatre - magic. So we have spent a lot of the time trying to make magical things happen."The Ghost's Child is performed at the Mandurah Performing Arts Centre from September 28-October 5.