A person with autism is not mentally ill, first of all. We have a few functions reduced or working differently, but in general autistic people are, ahem, kinda stable. You can live as an autistic person without treatment for all your life and be kinda adequate. Though one could also say that about narcissists.

People do have agency, but if a person is disabled in some way, their agency is reduced in those specific ways. A person with schizophrenia paranoid type has reduced agency when they are falsely accusing someone of taking their stuff or trying to poison them, for example.

Similar to how it doesn't make sense to hate a blind person for not seeing something or a person without a hand for not helping someone out of a pit, I dunno.

Getting back to autism, yes, I don't think it makes sense to expect social respect or conformism from autistic people and get angry for not getting them, or try to put autistic people in a hierarchy. Autistic people simply exist outside those. Seeing that something exists and being able to imitate it consciously is not the same as being capable. Autistic people should not be expected to obey common hierarchy or group dynamics, because it requires too much effort with nothing good for it.

And getting back to narcissism and schizophrenia, read the article again if you need - the description of her behavior seems very similar to those.