Educating Conservative Friends

This is a small rant combined with asking for advice about educating people who are well-meaning but also rude. So I have a friend from high school who has taken it upon herself to discuss her neighbor, an autistic man living alone, on social media. She consistently refers to him as an adult child, and she publicly states that he shouldn't be living alone with his condition... Knowing her, I know she is uneducated and really does mean well, but it makes me so angry. He does not know she's writing these things, and I know quite well that ASD indviduals can not only survive but thrive on their own. In fact, my boyfriend was much more motivated and happy when he was living alone rather than with his parents, as he's doing now. Does anyone have suggestions for how to educate people like this who are well-meaning but ill-informed and quite honestly rude? I'm finding it especially hard because my boyfriend is not public about his ASD, and I don't want to 'out' him by trying to inform via personal experience. I've read a lot of ASD-related materials, but I would have a hard time explaining to her why I've read so many materials that are unrelated to either of my degree programs. Basically, this woman is a strict conservative who has a holier-than-thou attitude towards anyone who is different from herself, and I need help figuring out how to best (and most kindly) tell her that she is in fact wrong and offensive in judging a whole wonderful group of people based upon one individual she may know... Thoughts?