This seems to clearly prove that Monroe's version was arranged from
exsisting songs in the area.

MOLLY AND TENBROOKS JOAFL 1915
From Kentucky Country: Folk and Country Music of Kentucky - Page 10
by Charles K. Wolfe - 1996
Journal of American Folklore 1915
These stanzas were collected from a man in Louisville:

Timbrook on the mountain, Mollie on the sea,
Timbrook says to Mollie, 'You can't get away with me."

Timbrook says to Mollie, 'What makes your feet so round?"
"Before I let you beat me I'll never touch the ground."

Mollie in the stable a weary and a-cryin',
Timbrook on the racetrack gone a-skippin' and a-flyin'.