Poet Anne Bradstreet (of Puritan Massachusetts) mentions singing lullabies in her poem "The Four Ages of Man," published in 1650. An excerpt:

With wayward cries, I did disturb her rest;
Who sought still to appease me, with her breast.
With weary armes, she danced, and Bye, Bye, sung,
When wretched I (ungrate) had done the wrong.

Sorry I can't be more specific. Margaret