My philosophy is that any step in the right direction is a good meeting. You did make progress today, got accommodations, and got them thinking.
Start collecting evidence now. The social studies tests are great examples. It's not about getting 100%, but about being able to show what she knows. In future meetings, you'll have more evidence and you'll have a more fluent ability to discuss her difficulties. One point to start making is that a kid with school engagement, high grades, and high IQ is on target for honors and AP classes in high school. These are writing intensive classes. The school needs to find a way to start lowering the barrier for her to produce written work now such that she can grow towards that goal.
Have you met with a SLP for an evaluation? Some of what you say hits a language red flag for me. The fluency of developing ideas is something SLPs can address.
