At this point in the year I would probably let it go. But does she have concrete input or power re your child's future? Does he need a recommendation from her? How does the process work? Here, the wheels do go into motion through teacher rec and then it's all straight test scores after that--no further teacher input. I believe you can also submit outside test scores if your tester has the proper qualifications.
There really are some teachers who dislike the concept of giftedness and seem to be hostile to bright kids and their parents. I've only skimmed proteacher a few times, but I've seen it. To be fair, some parents contribute to this.