Anxiety is manageable with benzodiazepine but I would not recommend it at a young age.

I think your child might have autism; which as you described has social disorder.

To people she knows is possible to interact normally but I have a friend with also a girl with autism, socially its a bit off, might want get it checked.

Have a proper doctor to evaluate, it will help if known earlier, then you can adjust your lifestyle according to your daughter.

Wish all the best.