I'm not sure. but u can get the notes online
I found it on this web site www.scribd.com/doc/8468927/bellas-lullaby Check this out. it says piano but its also for violin http://modernpianomusic.com/wp-content/uploads/2008/12/bellas-lullaby-carter-burwell.pdf
Bellas Lullaby is the music that Edward plays for her on his piano. It is played in the movie, but not addressed. If you buy the soundtrack, you can hear the entire song.
Go to this site, it is free and GREAT http://www.pianomusicsheet.net/bellas-lullaby-edward-carter-burwell/
The music is called Bellas Lullaby.
No, Bellas Lullaby is written by Carter Burwelland River Flows in you is written by Yiruma. These two are separate piano pieces.
See related links.
you can try it on youtube to get the twiight paino notes or on google