Story plot - Vamp Revenge - unfinished

Dad and mom fight. Dad kills mom and 3 kids. Ties them up with silver embedded duct tape and lays them together in bed. Daughter is under mom and mom's blood seeps from slit in her neck onto daughter's mouth. Daughter lives off mom's blood for 3 days before police bust in and go for dad, who escapes. Daughter revives in hospital and vows to avenge mom. Turns out mom was vamp and dad is some type of warlock. Kids weren't his - daughter is only on who inherits powers. Mom found low-paying job in Dad's company and worked her way up. Dad was impressed by her and asked her out. Became abusive after wedding.