I'm sorry to hear of your daughter's horrific experience, Mark.
I have had the same experience on only 100mg Seroquel while ramping up to a target of 300mg. After 10 days I was still so sedated and unable to function with normal daily activities like driving kids to and from school or help them with homework that I decided to taper off and look for another solution. I felt I was more dangerous on Seroquel through incompetence, frustration and hopelessness than I was off it.