in season 6?
No she doesnt die..Lucas and her just leave Tree Hill, after their baby is born. So they wont be coming back for the next season.
Only Haley, Nathan, Brooke and Julian will be in the 7th season. Plus some new characters will be returning, like Quinn, Haley's elder sister and some others.
Oh and yeah rumours are Rachael will be returning aswell. :D