Mary Downing Hahn
Diana and her younger brother, Georgie, have been living alone on the grounds of the old Willis place for ages. They've seen caretakers come and go, but the new one seems different. Mr. Morrison has a daughter, Lissa, who seems to be about Diana's age. Both girls are lonely and long for a friend but Georgie reminds Diana that it's "against the rules" to have friends; that they must remain out of sight. But Lissa remains intriguing to the children. She not only has a bicycle, but she also has many books and a stuffed animal that reminds Georgie of one he once had. They share even more; Lissa, too, has suffered a huge loss.
