I don't get it.

I just reread a book I read in 7th grade, Elli, Coming of Age in the Holocaust byt Livia Bitton Jackson. Last year I read I Have Lived a Thousand Years: Growing Up in the Holocaust (Hardcover) by Livia Bitton-Jackson. Same story, same author, different books. I don't get it.. is one for kids and one for adults. She's written a lot of books...Like 4-5 biographies... I find something about it odd. Don't know what but odd. I can understand maybe 2-3 biographies but 5...
Anyway they are
Elli: Coming of Age in the Holocaust by Livia E.Bitton Jackson
I Have Lived a Thousand Years by Livia Bitton-Jackson
Towards Freedom by Livia Bitton-Jackson
Hello, America by Livia Bitton-Jackson
My Bridges of Hope by Livia Bitton-Jackson