My hunch is that even without an IEP to 'make' the school help her, the school may give her services because it is their mission to help children.
That could happen. In our experience, though, it's unlikely. Actual services (such as PT, OT, speech, remediation of dyslexia by a reading specialist) are doled out minute by minute to those who qualify for them through testing and push for them in meetings. For children with IEPs, there is supposed to be federal and state money flowing into the school to fund those services. For children with no IEP, there is no extra money coming in: the school would be paying out of pocket. It happens, but not too frequently.
If you only need the accommodations (adjustments to assignments, that sort of thing), that's awesome, because they don't tend to cost the school any extra money and are much easier to get.
Wishing you luck,
DeeDee
