She does not go to school yet. We do her therapy at the school though but their are no other kids in there with her. This is just at the park or when we walk by the kids in the school cafeteria or playground.

Great. So what are you doing regarding the noise levels? Have they been addressed in her classroom? Are their accommodations to let her use ear plugs or noise canceling headphones to limit overstimulation?

It really seems to bother her when kids are really loud and screaming. She doesn't like for them to come towards her either. The more kids around her the worse it is. She does have a hard time with change.

When my son was that age, he didn't have the flexibility to accept changes in his routine or surroundings. One thing that I have learned and continue to do is to pre-coach, meaning I over talk about the new situation if I am aware it will change. My son also has sensory issues to smells, (even people smells), lighting and noise levels. He gets overstimulated in a crowded room or gym class with the echoing and louder noise levels. Could these be having an impact on your child? Routine is still quite important for my son (now age 13), he is maturing through some of these issues. Yet, last week, we had 3 severe meltdowns due to noise levels in the classroom and it had been about a month since the last meltdown. At age 5, we had several meltdowns each day - but then we weren't diagnosed with autism and really confused.