Tiny nuns.
Ahhhhhhhhhhhhhhh!
Maybe they mean "closets" or "pantries"? Sounds like someone is not a native speaker of American!
It's an "old European" (or, rather, an American colloquialism by now) to use the word, "cupboard" to describe/define a closet.
So, the statement ("nuns...sleeping in cupboards...") probably means they are sleeping in closets.
Some folks in rural areas in the U.S. maintain the language of an older time, or, maintain the expressions that are still commonly in use in areas of Europe from whence their ancestors originated.