Since working with non-verbal students I have found they are usually surrounded by adults, which is understandable but I have also learned some of my most valuable lessons from watching how students interact with students with disabilities. Giving peers a little understanding of their classmate, and allowing them to be creative while the adults take a back seat can be eye opening. Kids naturally know how to chit chat with their non-verbal friends, laughing, being silly and just being kids.
I have come across the quote "if you want to know how to act around someone with a disability, watch their siblings". Here is a 'informational' video by Abby showing one way she communicates with her non-verbal brother.