Looking for an old book in spanish 1940-50's approx!!!?

It's call "Bajo la sombra del claustro" and it is about the ugly true about the girls who are catolic and gave there life to serve God and some of this girls where severly disciple and some of theme where pregnat by the father and if they didn't want that the parents know about this they burry the girls a life in the walls with the babies......this is history in mexico, some churches that are now museum they tell you that, because when they remodelated the church they found the bones of little tiny bodies and the big ones who where the moms,thanks to everyone