'Chamalkay' is an old Guyanese slang word. It means a 'young mischievous girl.' It's not derogatory, but it isn't over complimentary, either. It was probably a word I just Googled one day, and the song kind of played into the feel of that.
I love learning about different dialects and I own all sorts of regional and time-period slang dictionaries. I often browse through relevant ones while writing a story. I also read a lot of diaries and oral histories.