Jean Nielsen (1922 - ) wrote several children’s books. The one horse book I have been able to track down is this one, The Phantom Palomino. I have not yet been able to find any biographical information on the author. If you know of any, please contact me.
Finding the book:easy to find in the USA. It was not published in the UK.
Links and sources
Terri A. Wear: Horse Stories, an Annotated Bibliography, Scarecrow Press, 1987
National Library of Congress
Bibliography - horse books only
The Phantom Palomino
Funk & Wagnalls, New York, 1966, 126 pp, illus Vic Donahue
Young Readers’ Press, 1969
A ghostly palomino horse and its Spanish rider ride through the lemon grove at night. Penny, Marvin and Marilyn try to solve the mystery of its appearance.