Jenny Luithlen, who was my agent for more than thirty years, died the Sunday before last, aged 80, after a long illness. She specialised in Children’s and Young Adult Fiction, with a warm but insightful eye, taking no nonsense from publishers or her authors, most of whom viewed her with affectionate respect. Born in Ipswich, where her father was stationed during the war, Jenny worked for the publishers Hodder and Stoughton for 22 years before forming The Luithlen Agency in 1986. Her clients including the pony-story writing sisters Josephine and Christine Pullein-Thompson, taboo-breaking YA novelist Robert Swindells, Pete Johnson and Alison Prince. Jenny and Lutz’s daughter, Penny, joined the agency after graduating, soon bringing on board her former school-mate, prize winning author Bali Rai, and…