In an anthropology class, I had to read an African folk tale that resembled the story of Barbara Allen. I wondered if there was any relation. My fuzzy memory seams to recall that it involve a young warrior and maid from enemy tribes dieing in an attempt be together. They are buried miles apart, and plants growing from their graves form a bridge between them. In that tale the deaths were by natural causes.
In some cultures such mysterious deaths as in most versions of Barbara Allen would be seen as a sure sign of magic at work. I always thought she poisoned him and committed suicide. Sometimes I think his friends were unfair to her seeing as how she's willing or at least expecting to die for him as well. Other times I think that if she murdered him, that isn't very romantic, and she got what she deserved.