My dd is doing the same thing, I try to let her call him, any chance I can. He doesn't usually answer, but she leaves him odd rambling messages and stuff. I think it helps her a little. I also try to tell her when he's at work or sleeping, that way she can start to understand that at night daddy is working and in the mornings daddy is sleeping, its help minimalize it a bit. And I sked him to call her sometimes and for him to tell her his schedule too, so it doesn't seem like I'm making excuses for him. I hope you can figure something out for you ds. I think the phone calls would be a great idea.