Wherever It Is Summer — Tamara Bach

The last thing either Jana, 13, or Louise, 17, is looking for on this hot and boring summer is a friend of totally the wrong age. But then one day, they abandon their responsibilities and irritating families, and head off in a "borrowed" car for a day by the lake. Their adventure is simple -- beer, ice-cream, swimming, singing -- but the friendship it forges between them turns out to be profound. When Jana experiences loss, it is only Louise's tender and funny postcards that can haul her out of depression -- right out of her bedroom window and off on another adventure.