After 53 years in children's book publishing, Margaret McElderry has announced that she will relinquish her role as v-p and publisher of Margaret K. McElderry Books at Simon &Schuster. In her new role as editor-at-large, McElderry will continue to work with her core authors. Emma Dryden has been promoted to senior editor of the imprint. She will oversee the entire McElderry list, reporting to Brenda Bowen, v-p and publisher of the children's division, while Karen Riskin has been promoted to assistant editor.