Demi Lovato has a notorious vault of unreleased songs. Leaked tracks like "I'm Just Me" , "Wrong" , or "Better with Words" circulate in private fan forums. It is possible that "Eveline" is an internal working title for a demo from the Unbroken or Demi album sessions that never saw the light of day. A low-quality demo could have been converted to m4a (Apple’s preferred AAC format) and shared on peer-to-peer networks.
If you have more details about the song (like from which album or year), it could help narrow down the search. Demi Lovato Eveline m4a
: You can find the full verified lyrics for "Eveline" on Genius . Demi Lovato has a notorious vault of unreleased songs