Jessie Nelson  wrote the book on which a musical was based which featured the song She Used to Be Mine.
"She Used to Be Mine" is a song written and recorded by American singer-songwriter Sara Bareilles for her fifth studio album, "" (2015), featuring songs from her stage adaptation of the 2007 film, "Waitress". 
Waitress is a musical with music and lyrics by Sara Bareilles, and a book by Jessie Nelson. 
