If you can get her through this year would you be prepared to homes hook both kids next year? If I were her I would resent having to go to school when my brother didn't (bad enough when the sibling is a pre-schooler). If you explain (possible for the 100th time) that you can't do it now but you will next year and come up with a plan for her she may rise to the challenge. I would also check out the specials teachers - maybe she is scared of them or their classrooms or something.