Elizabeth Grant wrote several songs (though Roy's Wife is her best known). She also wrote Rising of the Lark (http://www.contemplator.com/folk2/riselark.html). Well, o.k. that makes three for certain - but I'm sure I've run across others as well... How's that for an unverified fact? Oh dear - wish I had time to look through things..
A short bio of Elizabeth Grant is at Elizabeth Grant (http://www.users.globalnet.co.uk/~crumey/elizabeth_grant_i.html) At Andrew Crumey's wonderful site on Scottish Writers.