I recently watched again The Shining and I noticed something that confused me. At the begining of the movie, the guy who hires Jack Torrance says:
My predecessor in this job hired a man named Charles Grady as the winter caretaker. He came up with his wife and two little girls of about 8 and 10.
But then during the movie we see that those little girls were actually identical twins. I've look about if this is a plot mistake or it’s intentional but I cannot find much information, beyond "they are not because it is stated they are a different age" or "one is slightly taller than the other" (which seems surprising as the actress are actually twins, according to IMDb).
So is this a plot hole or was it intentional?