In the Canadian Journal for Traditional Music, 1979, Edith Fowke comments on an article about a "French-Canadian ballad "Le garçon empoisonné" which is not known in France and is apparently an Acadian translation of a well-known Child ballad, "Lord Randall." It might be noted that a similar process probably produced another Acadian ballad, "Ou vas-tu, mon petit garçon? which Marius Barbeau published in Alouette (Montréal: Lumen, 1946, pp. 161-163). Again it is a song not known in France and parallels closely another Child ballad, "The False Knight Upon the Road.""
I have not seen the text of this ballad, so how close the 'paralelism' is, I don't know. Both are 20th C. collections; age and how similarity was arrived at is unknown.
"Le garçon empoisonné" has been recorded on the cd Traditional Music of France, Ireland & England, Green Linnet SLP 1011 by John Wright and Catherine Perrier.
http://cjtm.icaap.org/content/7/v7art1.html

These songs are being sung by several folk singers which is fine, but without knowing more about their origin, accepting them as old Acadian folk songs may be a bit like accepting "Ring around the Rosie" as a song from the time of the plague.