My aunt has hair three quarters long. That means that it is long enough to come to the knees or maybe just past, 3/4 of her height. She wears it in a braid most of the time. Her braid is a thick as my wrist on the source end tapering down to a bout an inch in diameter at the end.

Most of you fortunately have never had to move a large dead body. I raise sheep and have had to wrestle some dead ones occasionally that weighed 3/4 of my own weight. "Scarcely find her marrow" is to how light boned the girl is. I had a roommate in college that this always makes me think of. She was my height (5'4") but while the diameter of my wrist is 8.5" hers was about 6 inches. She had a very elfin appearance and only weighed 90 pounds.

I believe that the reference to wrapping the hair around his middle refers to the method that she employed to carry the body away. She has used her braided hair as a rope to stablise the load of his body so she can walk away with it. She may not have even cut the hair to do this but left it attached. Look up a system of packing called tump lines that was used by early American Indians and Eskimos (and probably lots of other early people).