Wagner arrived in Australia when she was nine years old. Her studies at Melbourne University included German, Dutch, Swedish and philosophy. Her books are informed by both her studies and the disciplined use of language required in script writing for the Australian Broadcasting Corporation serial Bellbird.
The former proprietor of a coffeehouse, Wagner also published The Sourdough Cookbook in 1992.
John Brown, Rose and the Midnight CatThe Macquarie Bedtime Story Book
1977single work picture book children's 'Rose and her Old English Sheepdog, John Brown, live contentedly together. They need only each other. When the midnight cat appears outside their home, John Brown refuses even to admit its existence. But he comes to realise that the cat is important to Rose and to allow it in the house, even though it makes him sad.' (From the publisher's website.)