A diagnosed child or a typical child...I think this is a problem with all parents. I have had concerns with my son also in regards to this. He started picking up some bad habits from a child in his class. Maybe you can discuss with her teacher what kids in her class would be good to ask on a play date. Take them out or invite them to your house. Most parents would be receptive and return the gesture and do the same with her. Because of their relationship and connection outside of the classroom, it will develop into one in the classroom.
You could also get your daughter involved with a dance class or some sort of organization outside of school to make friends. My son is diagnosed with PDD and we had him on a soccer team. We didn't tell the coach or anyone that he had a "diagnosis" and to tell you the true, he fit it just fine. I'm pretty sure all the kids didn't have issues....some where fooling around, the girls were doing cartwheels right in the middle of practice...no one listing to the coach; they were all 7 years old, very typical. They were all nervous on game days as well.
Good luck. I hope some of this is helpful!!!