The Siren's Lullaby (Isekai Book 2)

Mavis's first life was pretty pathetic. She was abused and grew up as a timid person who was constantly beaten and hated but everything changed when a war ensued and she died, only to wake up to another life. A better life, in the modern world where every single thing was better but it didn't last long. She died in an accident at the age of twenty only to come back to her first life exactly where she left off.