I'm afraid it isn't. The lyric will still be in copyright, and so will Sylvia Barnes' arrangement, whatever the status of the tune she set it to when played on its own. Copyright details are: "Violet Jacob/Sylvia Barnes; pub. Kinmor Music" (presumably 1979). MCPS will have the full details. Sheila got permission to set the poem from Violet's niece and heir, Millicent Lovett.