Most people I talk to have no idea that children with an ASD smile, can be social, or want to be social.
My dd will tell you she has friends if you ask her. She'll say she has a lot. Ask her how many and she'll tell you that she has "billions." The real problem being.. she doesn't know what a real friend is and has no way to discriminate something like "friendship." Its that same thing that keeps her from being able to decide if something is a "big deal" or a "little deal." (someone bleeding=big deal. Dropping her fork=little deal. Both cause her to scream, cry, flap, hyperventilate, etc.)
I can't tell you how many people see a snapshot of her day. 5 minutes at the store. The first meeting with a new therapist, etc.. and they are shocked to hear she has Asperger's. Nevermind the Anxiety Disorder and ADHD. They see a moment and they judge her for "normal" and then I'm left to prove something. I used to feel awkward. Almost like I was pretending. Clearly I was wrong. Here sat a quiet, polite child. Where was the one that screams and flaps and repeats words over and over while pacing and jumping on my couch? Where is the one that stares off into space and shuts down verbally? ... Eventually I learned to use the words, "Good office presence" so that other knew she can fake it for a short period of time. Instead of convincing people, I only have to say.. Give it time.

Remembering that its not possible for people outside my home, to see my childs entire behavior. Its only a snapshot! A small piece in time. When she was younger it was easier. Her behaviors were more predictable. Now that she's older, she really doesn't want to lose control and have a meltdown. She wants people to like her. She has such anxiety about people finding out that she acts like that, that she is capable of trying to hold it together. Every year at school it gets harder and harder for her though.
Oh, and btw.. yes. She is pretty. Yes its still possible that she has autism, even if she is pretty. I find that to be a very ridiculous assumption.