Ask the Passengers - A. S. King

Astrid Jones desperately wants to confide in someone, but her mother's pushiness and her father's lack of interest tell her they're the last people she can trust. Instead, Astrid spends hours lying on the backyard picnic table watching airplanes fly overhead. She doesn't know the passengers inside, but they're the only people who won't judge her when she asks them her most personal questions . . . like what it means that she's falling in love with a girl.