So, I plan to set up an appointment to talk with her to see how/whether they might be able to accommodate DS.
Good! I would strongly encourage you to do this.
I'm also going to ask her if she can point me to this research against ability grouping at a young age.
I would strongly encourage to NOT do this. If you want to help 'all the children' do it at a school your child doesn't attend, or talk to your Representatives, or write letters to the editor. Keep your focus on your own child, especially now when you are just starting your relationship with the school. First things first. Engaging in a theoretical discussion doesn't further your chiild's education. Instead you can play the 'social and emotional needs card' and say something like: 'I've observed in other settings that my child remains shy and withdrawn/acts out if there are not a handful of other kids in the room of similar academic ability. Is there anyway you can put her in a classroom with other similar kids? Thanks'
You have to speak the language that your listener can hear.
Best Wishes,
Grinity