allmusic lists 293 recordings of various songs called GRACE—which seems like the most likely title of your song, since Googling with any other phrase from your lyrics turns up nothing.

You might try listening to sound samples until you hear something you recognize. I listened to all the ones that were labeled "folk," but none were duets, or had any lyrics that seemed to match what you quoted. Allmusic's genre labels are not very reliable, though; for instance, it seems that everything gets the default classification "rock" if they don't know what it is.