A tiny bit marvellous / Dawn French.

The story is told through the eyes of a mother and her two teenage children. There's seventeen-year-old Dora, a stroppy teenager who's just come out of her first relationship (it lasted a whole six weeks) and who's longing to escape to university; her long-suffering mother, Mo, a child psychiatrist who's baffled by the antagonist behaviour of her children; and sixteen-year-old Peter, who prefers to be known as Oscar due to his obsession with Oscar Wilde. Written in diary format, with each chapter narrated by a different voice, this is a hilarious, sharp and utterly compelling novel about the ups and down of family, sibling rivalry and growing up.