She tends to just play by herself a lot at school, looks for bugs, digs in the dirt, plays on the monkey bars by herself, etc. She also sits by herself at lunch (according to her, not sure how accurate this is and thought about popping in one day for lunch). *IF* she plays with others I notice she has to be the boss and direct/delegate her playmates and the play.
This is my DS8 too, although a bit less so this year. There are many days when I ask him what he's done and he'll say "play by myself." The other day it was soccer... I guess he was kicking around a soccer ball, alone.
The school staff tell me it's by choice. They say sometimes he wants to play with the other kids, and they welcome him (phew). They say it's "just his personality - often times he's happy by himself."
I remember the Kindergarten teacher being unsure about it: "I'm not sure if he wants to play alone, or if he wants to play with the others and just doesn't know how." Now that he's in grade 3, we know it's by choice.
Speaking of digging in the dirt - the first year our current principal was here (I think DS was 6, in grade 1) he wrote a little blurb about leadership in the school newsletter, and he talked about DS digging by himself in the dirt, and how it inspired other kids to copy him. It was pretty cool
