It's become trendy for everyone to diagnose everyone else. People should leave diagnostics to the professionals. It's not as simple as looking at a list of criteria and seeing what boxes can be ticked. Your client and her circle of people she talks with are bored with their lives and have found some entertainment value in thinking they can analyze you. It has given them something to talk about.

Don't feed into it, and please don't assign any credibility to what these knuckleheads have come up with. Don't even argue with them. They are being foolish and rude. If someone said that to me, I might say, "Yeah, that could be true." and immediately change the subject. Do not be drawn into discussions about this. Even if you really were autistic, that would not be an appropriate topic of conversation between your client and you. You are with her to do your job and provide a service. That should be the focus.

The "spectrum" has been expanded to include way more people than it used to, which I think is causing confusion. We now have famous celebrities broadcasting that they are autistic. I have my doubts about whether broadening the definition is a good thing. Originally autism was a severe developmental disability. Now it gets applied to anyone who is not perfectly smooth in social situations. I doubt that's a valid way of looking at ASD.