I looked up mCLASS, and found that it is a computerized outgrowth of DIBELS, with various components that are administered and analyzed through the same online platform. From your description, I suspect that your district has switched to using mCLASS:beacon, which consists of 4-6 item probes in various grade-level common core learning standards in ELA and math. I would imagine that if she found a set of items (which would all be one task) annoying, that she could have checked out or replied under protest for just that item set.
Keep in mind that, like most interim assessments, mCLASS is designed to catch low-performing students and flag them for intervention, not to identify high-performing students for enrichment. The ceilings are generally rather low (often determined by the grade-level setting on the assessment) on these quick and dirty measures. Plus, is this system new to your system? It's often administered on the computer, where a misplaced button press or keystroke could make all the difference.
You can try to get them to re-administer. It shouldn't take more than a few minutes to do. I would spend some time finding out where your DD's comments and attitude are coming from, first, though. (Sounds like you've made a start on that already.)
