New school year

Today was the beginning of the new school year...kassidy is in 4th grade and Shane in 2nd. Kassidy actually did good this morning at home before school. Shane was acting out though...he seemed to have a lot of anxiety. So we get to the school about 10min before it started and I get Shane to his classroom. Then kassidy decided to line up outside with the rest of the kids instead of going to the classroom. Not a good idea on the first day but might as well let her try. There was a lot of kids and parents and teachers in a very small area...even I was getting overwhelmed. Then I watched kassidy do something I never noticed her to do before-she started hand flapping (also known as stiming). She is 9 years old - is this new or have I never noticed before? It was shocking at first but then it enabled me to check in with her and for her to tell me after my prompting that she was "losing it." So we went to her class and she had down time before the rest of the kids came. I don't know if it was stiming for sure but I do know it let me head off a panic attack. Some parents of autistic kids don't like flapping/stiming and try to get there kids to stop doing it. I am now wondering how many attacks I could have avoided in the past if I had noticed this simple gesture.