My Grandmother was an Elmhirst (Rosa). She was killed by a GI mid WWII.
There is a book on Elmhirsts called "a peculiar inheritance" tracing back her family to a smallholding in Yorkshire with a hirst of Elms on it; the book contains loads of odd archive stuff on paternity suits and fines for trepass going back half a millenium.
Is this the same family? There must be more than one hirst of elms in England?