This is a song that goes way back to the British Isles several hundred years. Here's a little information from Wikipedia:
"The Twa Sisters" is a murder ballad that recounts the tale of a girl drowned by her sister. It is first known to have appeared on a broadside in 1656 as "The Miller and the King's Daughter." At least 21 English variants exist under several names, including "Minnorie" or "Binnorie", "The Cruel Sister", "The Wind and Rain", "Dreadful Wind and Rain", "Two Sisters", and the "Bonnie Bows of London". The ballad was collected by Francis J. Child and is also listed in the Roud Folk Song Index."
And apart from appearing in the folk repetoire in North America, the theme of the song is widely spread throughout northern Europe. There's at least 125 versions of it known in Sweden alone. It is also known in Denmark under the title "To Søstre". The Two Sisters. I sing that song somewhere else here among my youtube videos if you should be interested in hearing that version.