Steve G -

Interesting! The 'antiquified' version - and I agree, the language is pretty dreadful, although I'd say it's imitation Dunbar rather than Chaucer - is Child 13B; 13A has the refrain "Son Davie, son Davie".

In light of the way the song's developed in revival forms, it's interesting that 13B doesn't have anything about the quarrel, & has 'Edward' killing his father. 13A has him killing his brother, and

'It began about the cutting of a willow wand
That would never been a tree.'

There's only one other variant, 13C, which consists in its entirety of the 'quarrel' verse:

'It began about the breaking o the bonny hazel wand,
And a penny wad hae bought the tree.'

Which is a nice way of saying 'something really trivial', and avoids the suggestion that it was the beginning of something non-trivial.

There's a lot of crossover with the Twa Brothers, to the point where it's not obvious that 'Edward' (or whatever we're going to call it) really was a separate ballad. The 'quarrel' verse isn't in any of Child's Twa Brothers variants, though.

And I'm guessing that there's no support in traditional sources for Edward/Davie/whoever killing his sister - and hence no real connection with Lizzie Wan & co.