L.G.
It's an adult book, but it might help-- it's called "90 minutes in Heaven", a true story about a Baptist minister who is pronounced dead at the scene of a car wreck, only to come back to life 90 minutes later. It might help her to read about his take on dying and heaven. It certainly helped my aunt when she lost her son from cancer. My mom bought it for my entire family. It may give her a new perspective on things.
Good luck!