It's so hard to get a real picture of things at only 6. It sounds like you are really attuned to your DD which means she has a great model of excellent "social IQ". I see that gifted kids (like kids with ADHD and ASD) are often so lost in themselves that they miss social cues (even obvious ones like eye-rolling when they diatribe). Kids at 6 are egocentric anyway, hence why they often spend an entire playdate agreeing on a game instead of PLAYING the game. Also, there is no hard line between ASD, ASD traits, and eccentric. Old men with beards make diagnostic guidelines that cannot pinpoint the subtleties of each specific child.