Why does Corrie ten Boom never marry, and what are the consequences of this decision?

Corrie decides not to marry after the young man she fell in love with married another woman...... someone his parents approved of. As a result, she remained at home, helped in her father's shop, and enjoyed her family..... not to mention that she saved many people from the concentration camps.

It was not until Nollie and Flip came down the aisle together that I thought for the very first time of my own dreams of such a moment with Karel. I glanced at Betsie, sitting so tall and lovely on the other side of Mama. Betsie had always known that, because of her health, she could not have children, and for that reason had decided long ago never to marry. Now I was twenty-seven, Betsie in her mid-–thirties, and I knew that this was the way it was going to be: Betsie and I the unmarried daughters living at home in the Beje.