Oh--it is not really linked to 'Edward', most versions of which have a young man killing his brother and being questioned by his mother about it....(both of these old murder ballads-- and others, have been traced back to the 1500's or earlier and are found in various countries...especially Scandinavia)..(The version of Lord Randal given in the 'Digital Tradition' database is a pretty good representation of the basic story, though by no means the only one).