My father used to sing the version below to me when I was a child in the 1930's. He had acted the mother in a minstrel troup in Putney, London,in the 1890's. I have a picture of him all blacked up ( not politically incorrect in those days).

Go to sleep, my little piccaninny!
Brer Fox will catch you if you don't.
Slumber on the bosom of your old Mumma Jinny.
Mumma's going to swot you if you don't.

At least it sounded something like that!