I don't think that the original written words have any greater validity than the words as recycled over many years in Jean's memory. If anything the other way round - some of the edges have been rounded off to fit the needs of a song as opposed to a written poem. I think I prefer Jean's, especially the last line.
Songs need to develop variants. I sometimes feel. I know that when I sing my own songs they vary a good bit. The same way when you tell a story or a joke it won't be exactly the same each time.