Yes, in the final book, she was killed in a train wreck.
Yes, Lucy really did die. Lucy was a baby of a young couple that got pregnant by mistake, and they had abortion, killing Lucy. John Cooper is talking about an abortion in the song Lucy.
If you want me to spoil it for you... Then yes. She does die. But it's really complicated. Watch it, it's interesting. I read that the movie was sort of expected, but not exactly, the end really surprised me.
Lucy Somerset died in 1583.
Lucy Hastings died in 1679.
Lucy Thompson died in 1932.
Lucy Stringham died in 1893.
Lucy Baxter died in 1902.
Lucy Markham died in 1960.
Lucy Aldrich died in 1955.
Lucy Covington died in 1982.
Lucy Anderson died in 1878.
Lucy Wertheim died in 1971.