Siobhan was born in London to Irish parents and worked for much of her life for human rights charities. The Pavee and the Buffer Girl, her first published work, was followed by four novels which won over 65 awards including the Branford Boase, the Carnegie Medal and the Bisto Award. Siobhan died of cancer at the age of 47 in 2007, leaving behind the roots of A Monster Calls, which was completed by Patrick Ness. It won the Carnegie Medal and a raft of other prizes and has been adapted into a film. Before her death Siobhan set up the Siobhan Dowd Trust which uses the proceeds of her work to take stories to disadvantaged young people.