Helen Sherman Griffith (1873 - July 13, 1961) was an American author. An Iowan, she was the "prolific" author of the Letty Grey series of children's books, published by Penn Publishing Company of Philadelphia. She was the daughter of Hoyt Sherman and Sara Sherman, who was born and raised in Des Moines, Iowa at Hoyt Sherman Place. Helen's bedroom has been restored and is part of the Hoyt Sherman Place house museum.
