Why the name change? I read the religious order gave her the name Sister James. I assume McEntee was her birth name? Something to do with Vatcan Ii? It takes places just after... Seemed odd the nuns had names of men.
Depending on the order, sometimes nuns took the names of apostles or saints, instead of keeping their own name.
Black men and a whole lot of *beep* white men have had plenty fun adoring my ass JUNGLE JULIA
As the prior commenter said, many orders require their nuns to replace their birth name with the name of a saint, regardless of that saint's gender. This has nothing to do with Vatican II (except that it may have been MORE common before Vatican II for the namesake saint to be a male one).
You have heard of this already, even if you don't think you have--the nun (and now saint herself) known as "Mother Theresa" was not named "Theresa" by her family at birth--her original name was Anjeze Gonxhe Bojaxhiu. She adopted the name from Saint Thérèse of Lisieux (who, interestingly, DID have the name "Thérèse" as part of her birth name).