One of my great-aunts (who believed that children should be seen & not heard)used to use the phrase "san fairy ann to you" in the sense of "mind your own business"

My mother explained that it came from the French Literally this means "that does nothing" but is used in the sense of "that is unimportant" or "that makes no difference" I don't know if your san fairy ann is the same. Eddie :o)