So far, finding common ground has been tricky for DD5. She is not a "girly girl" (her teacher's words) so, though she'll play house and dolls with the girls at school, these activities are not her first choice. She would much rather build something with Lego or talk about worms. She often plays with the boys.
Like Blackcat's DD, my DD has found common ground with other kids through running and physical play. She loves tag.
This weekend we went to a birthday party for a little girl turning five years old. We arrived early along with a couple of other girls. While waiting for the other kids to arrive, DD tried to make conversation with the birthday girl. She turned to her and said, "It's great that you're turning five. A lot of toys have age requirements that start at five, so now you can play with them." Cue deafening silence and blank stare from girl at DD.
DD's confidence was a bit shaken and she came up to me and said, "No one wants to talk to me or play with me." I gave her a hug and said look there are some girls playing with stickers over there. She went over and joined them. Later she had a blast when they played musical chairs and a few other dancing games.
On a positive note DD has made a friend at school this year who she says listens to her when she talks about things she's interested in. DH and I were pleased to hear this as last year she was a bit of an outcast. I know from my own experience that finding her tribe may be a bit of a journey. I just focus on making sure that she keeps feeling good about herself.