I have a dear friend who has a daughter who I have known has autism since she was six. Her mom only shared that she had ADHD and learning disabilities. She went to a very good private school for children with learning disabilities and ADHD and each grade level had about ten kids. She got OT, speech, and social skills therapy and other therapies over the years. I couldn't believe not one professional said something about autism so I figured she knew but wished to share her challenges this way...or if she didn't, her daughter was getting all the same services (OT, speech, social skills, therapy with a psychologist, specialized learning in small classes).
About high school her mom started attending walks for autism and posting autism awareness posts and I mentioned my boy has Asperger's. She said her daughter was newly diagnosed. Her daughter graduated high school and is getting services as an adult now with autism. I think nearing graduation someone must have suggested that her daughter was going to need SSI and voc rehab and other things and maybe they should look into it.
I can't believe that her girl was never diagnosed all those years and professionals and it was so obvious. I would spend a few hours every so often with her and could check off criteria on the DSM list left and right plus some of the stereotypical behavior that isn't in the manual.
But it was never my place because she never asked my opinion to say anything.