Moomin, I shared your daughters thinking, and still do mostly to be honest. Most little kids in a school environment can turn scary without warning. I imagine other children's age appropriate behavior is incomprehensible to your DD a lot of the time.
BUT something useful - when I was somewhere between 10-14 my mother tried to read a boom called "feel the fear and do it anyway" as with many sensible things my mother tried to talk to me about I point blank refused. BUT she did manage to get me to listen to a 3 minute summary of the book and its probably been one of the most useful social anxiety tools of my life... Not having read the book I can't vouch for it 100% but my mother's summary was quite life changing.
It ran something like: our fears are there to tell us to be careful, sometimes that is warranted, for example fearing falling from high places reminds you to stay away from the edge, this is rational. However sometimes our fears are not rational. Walking into a room full of strangers and assuming everyone hates you on sight is NOT rational, they don't know you, they've got no reason to like or not like you, most likely if you are pleasant they will be pleasant. Think abou your fears, if they are not relational feel the fear, acknowledge it, and do it anyway.
I would NOT have been responsive to therapy, especially not group. OMG i cant think of worse torture. They may of course have had a similar message. But this provided a simple and concise tool I could think about repeatedly on my own and apply as I was able on my own. It did help.
