She died because after her and Piper got attacked by the demon, Leo only had time to save one sister, and he saved Piper, so it was too late to save Prue as Leo can't heal the dead.
Hope I helped
Piper has wyatt mathew halliwell and chris halliwell both in season 5But we don't know when Piper has melinda Pruedence halliwell because it is shown she is born in 2010 but we are hoping for another season when melinda pruedence halliwell will be actually born!
Piper had 3 children, Wyatt Mathew, Chris Perry, and Pruedence Melinda.
prue halliwell
Ernest Halliwell died in 1919.
Joe Halliwell died in 1964.
David Halliwell died in 2006.
James Halliwell-Phillipps died in 1889.
Kenneth Halliwell died on 1967-08-09.
Miles Halliwell died on October 6, 2004, in Farnham, Surrey, England, UK.
Leslie Halliwell died on January 21, 1989, in Surrey, England, UK of stomach cancer.
Halliwell Hobbes died on February 20, 1962, in Santa Monica, California, USA of heart attack.
The source sends an assassin to kill her.