What stopped your great-grandmother from converting to Catholciism? Is that in your “legend”?
I guess when you treat a potential convert like horsh** they have to question whether you are really Christian, and whether they want to join your church.
This started with her Catholic wedding being held in private in the sacristy because as an infidel she was not allowed to stand on the holy ground of the altar.
Would ultimately not let her be buried with her Catholic husband either.
In fairness the Catholic Church has come a long way in that regard since her day. They even play Away in a Manger in Catholic churches at Christmastime now.
And so it continues......
And why is he answerable for his great grandmother's decisions?
Probably the loving way in which outsiders are treated by Catholics, of which there are plenty of examples even here on this thread. Why would anyone WANT to consider converting to Catholicism if what they see in the way they are treated is evidence of the fruit of Catholicism?