Can you call the school and ask if they ever consider outside testing?
It depends on what your goals are for testing. We did not privately test DS until after receiving his Explore & ACT results. The school had attempted to do testing at 5 and he was completely uncooperative. We always knew he was gifted. As parents, we fell into the clueless category on levels on gifted. My DH wasn't even in total agreement about testing him at that time. I just needed to know for sure. I didn't have a clue if the school would look at his results or not. I knew he was very bright and bored in school. Every year I ask my DCs, "What did you learn in school this year?" Every year his answer was, "absolutely nothing!" He was drooling on the desk with bored and easy. The staff used to say, "they are getting homework everyday." I would have to explain that he would finish it before they were done assigning and explain it. He is 13 now and does actually have to do some work every day. I still doubt it takes him as long as other kids, but he is working.
Testing him has enabled me to advocate for him from a much more powerful position. I have a strong amount of data on him be effective with the schools. I have been able to get a substantial amount of subject acceleration and compacting done for him. He had expressed no interest in whole grade skips unless the school would only consider that. We have gotten a great set up of accelerations in 3 subjects ranging from 2 years and up. He does grade level History, Orchestra, Gym, and Chinese. It worked for us. Without the testing, I don't think any of it would have happened.
In testing him I recognized DD needed to be tested as well. She is a blender with her peers. The school never would have recognized her. They didn't believe our outside testing. We actually allowed them to retest on a different IQ and achievement test just to get them to move forward and see her.
If you are testing only for the school than make sure they will accept it. In the event you do go ahead with testing. Look at hoagies list of testers or even post here asking people for names. You've mentioned she is an introvert and I think an experience GT tester will be very important for her. If she is anything like my dd consider meetings to get comfortable with the new person before actually testing. My dd is very outgoing, but she is a stubborn perfectionist and uncomfortable with new people. It was vital she was comfortable with her tester before testing.
Personally I would choose the testing. It was absolutely helpful for understanding my kids. My DD is just under DYS criteria but her needs are still just as important as her DYS brother's needs. A lot of very gifted kids never test high enough on both achievement and IQ for DYS criteria. They are still gifted. Hanging around a site like this one can really skew ones view of the numbers. There are always scores that are higher than ones own kids. In real world, they are high scores and unusual.
