Thanks for the info folks. I checked in Child, but not connecting the film with the Bonnie Banks of Fordie, hadn't thought to read the headnote.

Having looked at the text which Maeve provided, the film appears to diverge from the ballad in several crucial respects. This is probably only to be expected. But it raises two questions.

Firstly, might there be other versions which are closer to the screenplay?

Also, there are several details which are in the film, but not in the ballad, but which which look to me like they might be Swedish folklore motifs in their own right. I'm thinking particularly of the sister putting the toad in the stottie cake, and the spring flowing up from where the corpse was laid.

Anyone care to comment?