To me, not knowing your DD, it sounds like the person who observed your DD had some thoughtful (and accurate?) comments that could possibly help you. Her comments seemed reasonable and well-thought out and didn't pathologize what she saw. Your DD is a healthy, happy, enthusiastic, smart kid! And I liked what she said about focusing on preschool for awhile as purely a social event. The nice thing about preschool, IMO, is that you do have time to do more "mentally stimulating" things at home, such as trips to the zoo, science museum, nature center, or backyard and things like board games or anything else that interests her. To me, the fact that her preschool is full of really nice kids, would be a reason to not worry at this point.
Now, when she goes to school full-time, you'll need to have a game-plan for academics!
