The daughter of Casper ten Boom, she is one of the leading characters in The Hiding Place, a book written by her sister Corrie ten Boom about the family′s experiences during World War II. Nicknamed Betsie, she suffered from pernicious anemia from her birth.What was Corrie's message when she began to speak? Her message was joy runs deeper than despair. The key to all the damaged people was the same.