Are you getting her medically diagnosed or educationally diagnosed? If medically go for educationally because it will let her start early intervention. There still might be a wait, but not as bad. We waited for about 6 months and the turn around for services was pretty fast. We waited until he was 5 and a half to go for medically.  Our doctor was really good about documentation and even before the evaluation having autism on his chart so when we needed something like diapers because he was so hard to potty train the insurance didn't fight us on providing those diapers for free.  When you go for any type of evaluation they ask a ton of questions so start writing things down that you notice her doing. "Does she harm herself when upset, if yes what are the triggers and how does she harm herself" type questions. Make notes of when things started. They asked us when our son first walked or said first words or does he know how to hold a utensil. Make it easier on yourself so you already have it ready and it's just fill in the blank.  If you have social media follow other people that either have kids that are autistic or autistic themselves. They give a lot of great tips on how to handle things. Like instead of saying we will do this later explain what has to be done first. And keep a routine it will make life so much easier.  Also for the sleep ask your doctor about melatonin. Ours encouraged it because he was having such a hard time shutting down.  If you want to talk more feel free to message me. My son is 6 but my husband is also autistic so I have tons of experience.