Title of this book? in the movie Orphan the mom is reading a book to her daughter and its about her little..?

sister who is now and angel. it goes something like this. mommy and daddy went to the hospital and when they came back they came alone. it says the sister is now an angel. (thats not exactly the words but thats the pretty much along the lines). iwant to know if thats a real book and if anyone knows the title? thank u for your help