> translated from the German

Yes, having read Child's headnotes more thoroughly it would seem more likely a Danish translation as in the original German poem there is no mention of the fairy being in water. The later Danish ballads 'Elveskud' were extremely popular and numerous. It would be an interesting exercise to look through the many Danish versions and try to pick out one that is closest to Shenstone's version. I have an abridged copy of Grundtvig.

Alas I don't know Danish and can only use those already translated into English at a later stage. Jamieson was amongst the earliest of the well-known Danish translaters

The Shenstone ballad could be a direct translation by a literary hand
'she found her spirits sink apace'. Hardly the language of tradition.