I'm not sure which state you are in, but I delayed mine starting 12months. She started at 5 and 9 months. Best thing I ever did for her.
She was still super stressed. Her teachers were awesome though. We discussed triggers with her. The teachers aide had come from the preschool and knew DD1 so that was awesome for us. Make her aware of what will happen, the processes, the things she will take. Get her to wear her uniform before so you can sort out any tactile stuff.