My son has an IEP for hearing loss. Frequently we have found that teachers forget about his IEP and don't follow it.
Maybe you could meet with the teacher and explain what the IEP is for and why, how she gets extended time on tests. I agree, she should get extended time on the tests (or maybe you can see how she does without it but it wouldn't count for the grade).
Possibly the teacher doesn't realize your daughter has an IEp or what it says. We have found that with our son.