Can I pray for the past to change certain aspects of life? (Catholic perspective)

I'd like to know if according to the Catholic teaching I can pray for the past events that didn't happen? For example: If a woman miscarried a child which means the child wasn't baptized and at that moment woman didn't know it was necessary for the child to be baptized in order to get in heaven. And now after some time she gained the knowledge and ask the angel in a prayer go back in time and perform the prayer of baptism over the baby. Or when some relative dies and after 5 years I gain the knowledge that the person might be in purgatory and maybe I should pray for the person. Can I offer all of my prayers I've done since and pointed them to the moment when the relative died? Will that be added to that soul to the moment of her death or only to the current moment? Is this something we can do according to the catholic theology? Or we can only pray for the present situations and is everything bound to the present moment only? I know this can be difficult to research but maybe someone can find something within the tradition.