Angie I don't know if this will help you feel more hopeful, but we have had an awful time with ds1 and getting him to nursery. When he was 3 he started at a nursery and for the first term loved it, then suddenly had a complete about face and was exactly like your daughter. We tried everything, from staying there to changing the class he was in, to the manager of the nursery lookign after him but nothing worked so we took him out thinking maybe he just couldn't cope. I am at home all day so it wasn't crucial he had to attend.
Anyway we moved home in september about 80 miles away. The hv here recommended a nursery for him after hearing how he had been previously, and as he was 4 in november he had to get used to being away from us ready for school. He started at the beginning of November and was exactly the same as in his previous one, crying, shouting begging not to go. When it got to the Christmas break I was relieved tbh because it was starting to upset me, although I was dreading sending him back in the new year, and told dh that if there was no improvement I would take him out again. So his first day back he did the usual routine, BUT when he got back he was smiling so hard his face couldve cracked! He said he had a great time and wanted to go again, and it was all down to the fact that some new children had started and he was asked to help look after them! So now he has done a complete about turn and is asking to go so much we have increased his days from 2 to 3!
Maybe your daughter needs something like this to help her? Being given the responsibility of helping another child settle has done wonders for ds, and he really was traumatised by the thought of it (used to ask every night before bed if he had to go again and start crying if I said yes).
Anyway this was really just to show you that she may well change her feelings about school yet, maybe she just hasn't found the right thing to help herself. Good luck to you both anyway.