Ya Chuck. Kind of like "brothers" means "cousins" in Matthew but golly there happened to be a "cousin" greek word in Luke used for Elizabeth. Whatever's convenient for them i guess.
The word used to describe Elizabeth isn't the usual Greek word for "cousin". It just means "relative".
Adelphos ("brother") is used to describe Lot's relationship to Abraham in the Septuagint text of Genesis, even though Gn elsewhere makes it clear that Lot is really Abraham's nephew. And the Gospels use adelphos to describe the relationship of Philip the Tetrarch to Herod, although secular history says that Philip was Herod's half-brother.
Whatever's convenient for them i guess.
If you want to dismiss the belief of a billion Catholics, 300 million Orthodox, and all of the major Protestant reformers with a sarcastic throwaway like that, I guess that's your right. But it's at least possible that maybe some of them are better Bible scholars than you. Don't you think, for example, that the Greek Orthodox probably know the Greek NT better than either of us?
If I were you, I'd consult with a Greek-speaking person before I said that. Just minimal fact-checking: so easy in the age of Internet.