Summer Days (Pen Pals Forever Series)

Polly and Jez are as close as two friends could be—two friends who have never met, that is. They have been writing to each other for as long as they can remember, just like their mothers and their grandmothers before them. When Polly spends a summer traveling in a caravan with her grandparents, it's almost like Jez goes along too. She has to travel in her imagination, of course, but with a little help from Polly's weekly postcard, that's no problem at all!