Do you see where I'm going with this? I'm not trying to twist your words, it's just that maybe what you want is obviously not what she wants. Maybe being sociable is not an essential aspect for her life. I know your friends are not monsters, but they are your friends, not hers. She's not obliged to greet them, especially when she finds it so distressing.

I can totally see your perspective though. If she wasn't autistic, she could just move out and live her life the way she wished. But instead she's reliant on you. Is there any help for your family? Any charities or community programmes? In the UK (where I'm from) there's a national charity who do a 'buddy programme'. A volunteer comes around and takes out the said person for the day. Are there any steps for your daughter to become more independant? You said she was high functioning. How capable is she?