A girl I went to school with in Ireland was baptised Bernadette when the priest refused to believe Natasha was a Christian name.
As with Marjoriew (Marjorie being a version of Margaret) it's unfortunate that there are probably a lot of ignorant priests and registrars out there. I think most priests would be happy to see anyone turning up to baptise a baby these days and would go along with the choice of name and play nice. My old parish priest even swallowed hard and went ahead and baptised a little Calvin about fifteen years ago...
I have relatives in Argentina who had to go through the courts there to give their children vaguely Irish names to honour their heritage that were not on the official approved list - probably 25-30 years ago.
In my own Irish family, there was an unspoken rule that names had to be not only Catholic but 'family' names. One cousin chose names for his DD that hit neither button and my uncle objected, 'That's not a family name,' to which cousin replied, 'Well it is now...