From what I've seen, when a student exceeds state standards on state tests the teacher is more relieved than impressed, and it doesn't make the teacher wonder whether that particular student needs more. Like others have said, usually the state-mandated tests are grade-level tests and so only really test knowledge at or slightly-above grade level. A more useful test IMO is the MAP test, if your school administers that, because it is an above-level test that allows a student to show just how much they know (there's a really high ceiling) and can be used to compare a student to other students in higher grades.
I completely understand why you'd want to use your DD's testing experience to advocate, though. And, I see no harm in using her experience as a starting point in a discussion with her teacher. But I would then ask if your DD can be assessed with things like the MAP or end-of-grade tests for the next year up. If you're wanting to get some changes in place for next year then this is the ideal time to get the process started because it can be a months-long process. First the meeting, then the convincing, then the testing, then the convincing . . . .
