My heart really goes out to you and your family. Children feel everything so intensely and are so very sensitive, all the while feeling powerless to change things. She just had her daddy, happy and safe with her while on vacation, and she must be so worried and stressed about him being away again. And now, he is blaming himself, when he clearly has no choice but to be away. And you're probably beating yourself up, wondering if there was something you could have done. An all around heart-wrenching situation.
But, you all seem like a strong, loving family, and I know you'll all come through this in the best possible fashion.
Sending you all the loving, healing energy I can, sweetie.