According to Pete Seeger, this song is sung at a folk festival that's held in Monrovia every year and the lyrics mean, "Don't cry, pretty little girl, don't cry."
Banuwa, Banuwa, Banuwa yo
A la no, nehniyo la no
Nehnia la no
Pretty little girl
If anyone can identify the language and confirm the lyrics and translation of this song, please email me. Thanks! -Mama Lisa
Thanks and Acknowledgements
This song can be found on the album "Folksongs of Four Continents" with Pete Seeger with the Song Swappers.