There is a version of the song from the collection "Later English Broadside Ballads" ed. John Holloway and Joan Black called "The Weaver and His Sweetheart". I'm not sure of the exact date but it would be late 18th or early 19th C.

It's mostly the same except that the girl is a servant rather than a factory worker. Personally I don't think it's overly fanciful that the song evolved naturally and someone along the way "updated" it and made her a factory worker instead without the intervention of AL Lloyd or anyone else!

The version in the above book also contains the following verse which might seem to suggest that the song is Irish in origin (the notes also state the song is Irish) :

My love she lives in the country of North
And I myself live a great way off
And when I weave in the county of Down
Then I will weave her a holland Gown.