Susanne(skw), when I was very small, my grandmother used to sing that to me. However there was no problem with "wee" as it wasn't in her version.

He's ta'en oot a knife, i t'was lang an't was shairp
An' plunged it right in t'his bonnie lassie's hairt
He plunged it right in t'his bonnie lassie's hairt
And there laid her low among the roses.

She seemed to put great, Victorian, sorrowful, emphasis on the word "plunged" and as a small child, I was impressed. LOL