Why didn't they learn Italian?
So these old English ladies have lived in Italy for many years, there are at least four years actually shown in the story and who knows how long they lived there before the story began. Certainly Hester Random, as the wife of the British Ambassador, had been in Italy for many many years prior to her husband's death, not to mention remaining there many years after his death.
Yet, she could not understand any Italian, and in fact, only one of the old ladies could understand any Italian at all. Are we expected to believe that, in all this time living in Italy, none of them ever learned any Italian?
"Enough of that technical talk, Foo!"