Claire Bolderson profiles Sarah Brown, the wife of the prime minister. She introduced him at the Labour Party Conference again this year and she is growing in popularity among delegates and activists who warm to her personality and read her Twitter messages with interest. But is she simply a 'first lady' who owes her influence to her husband's political status, or is she successfully carving out a career behind the scenes, working on her many charities and restoring some of the political ground that the Labour Party has lost? We talk to childhood friends, former colleagues and those who know her now.