Samantha's ideas and questions about Ginger will probably change as she gets older. Books can help her express those questions.
Here are some children's books on grief. Check your public library. One can pick the ones that are consistent with one's beliefs. The ages give the reading level, not the comprehension level.
Davis, Christine, For Every Cat an Angel, 12/2000 (Ages 4-8)
http://tinyurl.com/6mbkw
Davis, Christine, For Every Dog an Angel, 9/2003 (Ages 4-8)
http://tinyurl.com/6mbkw
Demas, Corinne & Hoyt, Ard, Saying Goodbye to LuLu, 6/2004 (Ages 4-8)
http://tinyurl.com/4h94p
Disalvo-Ryan, Dyanne, A Dog Like Jack, 12/1999 (Ages 4-8)
http://tinyurl.com/6f68o
Harris, Robie, Goodbye Mousie, 9/2001 (Ages 4-8)
http://tinyurl.com/4lqlj
Newman, Leslea, The Best Cat in the World, 2/2004 (Ages 4-8)
http://tinyurl.com/4rsxx
Pomerance, Diane, When Your Pet Dies, 6/2001 (Ages 4-8)
http://tinyurl.com/4m9yn
Puttock, Simon, A Story For Hippo, 9/2001 (Ages 4-8)
http://tinyurl.com/4se58
Rogers, Fred, Mr. Rogers Pet Dies (First Experiences), 5/1998 (Ages 4-8)
http://tinyurl.com/4ydoh
Rylant, Cynthia, Cat Heaven, 9/1997 (Baby-Preschool)
http://tinyurl.com/4e9p7
Rylant, Cynthia, Dog Heaven, 9/1995 (Baby-Preschool)
http://tinyurl.com/6jla3
Steele, James, Sadie Listens: An Inward Journey, 2/2003 (Ages 4-8)
http://tinyurl.com/5z3lc
Wallace, Bill, No Dogs Allowed!, 4/2004 (Ages 9-12)
http://tinyurl.com/4zyhj
Wilhelm, Hans, I'll Always Love You, 12/1988 (Ages 4-8)
http://tinyurl.com/43aoz
Zolotow, Charlotte, The Old Dog, 9/1995 (Ages 4-8)
http://tinyurl.com/6tzhl