My daughter has SM. She was diagnosed at age 4 after she went the entire school year not speaking to anyone at school. She is 5 now and in 5K. She still does not speak with anyone at school. She also cannot eat at school in the lunchroom, so she eats small amounts of her lunch at snack time. She was not able to use the bathroom there, but now can, because they let her use the private staff bathroom.
She see's a therapist who specializes in SM and is now getting to the point where she will whisper answers to his questions into my ear, while he can kind of hear. He responds to her answer as if she said it out loud to him.
She does not speak with any of her friends, any of her grandparents, any of her aunts or uncles. She only speaks with her immediate family (us in the house).
She now will make eye contact with people she knows well and will sometimes shake her head yes or no to their questions.
I am working on getting her an IEP or a 504 through the school so that she can meet her learning goals and continue to get accommodations. Her therapist is available if her teachers have questions.
The more she is around someone the more receptive she is towards them. Thus, playdates, groups and extra curriculars have been helpful. Ballet was not a good choice for her. I think all the mirrors really brought out the fact she was in a big room full of people looking at her. She would spend the session rolled in a ball on the floor. Gymnastics has been great though. For some reason she is thriving doing that.
Feel free to send me a message if you have any specific questions.
There is a Facebook group for parents of kids with SM. Lots of helpful info on there too.