Prince, Royal, Queen and ...
Pope.
The family is not Catholic.
I'm not really surprised by the first three names, though they are cringe-worthy as a sibset. But Pope seems to cross the line into offensiveness, since the Pope is the head of a specific religious group, a group to which this family does not belong, and Catholic parents would not use the title as a name; I'd imagine they would name after a particular pope if they wanted to honor one.
You're entitled to your own opinions. You're not entitled to your own facts. -- Daniel Patrick Moynihan