I have an AP who has the kids in the afternoon only too. She has generally been taking them to the pool or on a short outing like minigolf or frozen yogurt. She hasn't shown much initiative on getting playdates together, but oh well.
I think a family outing with all of you might help. Occassionally we take our AP out to lunch on a weekend and it is nice to talk to her about schedules changing, school activities, her upcoming travel month, her friends, remaining classwork, the car and such at a time when we aren't all just off of working all day.