She has also written the Me, Jill Robinson series of books, the Jug Valley Juniors series, A Horse Called September, Quicksilver Horse and The Big Swim of the Summer. She added six books to Enid Blyton's Naughtiest Girl series and created the Three R Detective books for younger readers.
Though her books have been out of print for a while, Fidra Books of Edinburgh has recently republished Secret Letters at Trebizon, which has a foreword by Digby.