I think Lady Jane's experiences in England are more to do with the personality of Lady Jane than the fact she is American. My own experiences of Americans over the last sixty years are that the vast majority are very nice, polite people but there are a tiny minority who are rude, loud and obnoxious who will quickly bring out the worst in the locals. Also as far as ice cream is concerned you get what you pay for and plenty of American brands are on sale everywhere.