Dick und Dallie und die ponies Translated as Snow Ponies University of London Press, 1960 Illus Princess Marie Luise of Salm
Ursula Bruns is a German author: as far as I know she has had only one pony book translated,the charming Snow Ponies, which was turned into a film, Die Madels von Immenhof, in 1955.
The front cover of Snow Ponies, with two of the lovely illustrations.