Conrad Bladey has posted two songs that mention Bella Roy:

• Lucky's Dream
• Euphy's Coronation

Are either of those the song you're seeking?
I don't find it in my copy of Come All Ye Bold Miners, but mine's not a first edition.
Not in the Traditional Ballad Index, either.

Here's a recording of the song by a group called "Tramps and Hawkers"

https://www.youtube.com/watch?v=8qLcohQvKUE

Not clear enough for me to transcribe. I'm far better with Midwestern U.S. English...

-Joe-