M.
You said your daughter has a couple of other friends. I would really encourage these other friendships. Invite them over for play dates find out if these other girls are involved in any outside school activities and then talk to their moms about signing your daughter up for one--if she is interested. I would continue with the carpool, but don't force the friendship or contact the mother-heck she doesn't return your calls anyway! Talk to your daughters teacher about possible girls in the class that have the same interests as your daughter and set them on a an outing or play date. It sounds like your daughter might be shy? If so, you might have to take the initiative for her, at first. Trust me, I found my daughters' friend in Kindergarten, i sat back and watched the kids one day after school, and pointed out a girl and asked my daughter her name. She asked why and I told her "Well she was wearing a dress with horses on it, and she likes to swing--two of your favorites" Well sure enough the next day they were the best of friends. So I made a point to meet her mother at pick up one day, and it has made our year soo much better! But, the teacher will be a wealth of info as well. Good luck.