Billy Graham’s children are thankful for their father; they just wish he’d been around more. When Franklin Graham was five, his famous father was in Australia for six months preaching at a Billy Graham Crusade. Like many youngsters, “I'd wake up in the morning, go down the hall and crawl into bed with Mama,” Franklin says. “Well, one day I went in and Daddy had come home. So here he was, this man in her bed. I asked Mama, ‘Who's that?’” Billy's children say that his frequent extended absences marked them, but so did his unconditional love. While he sometimes…