The Queen honoured America by having her guards play the US anthem at Buckingham Palace right after the attacks. Sadly many did not follow her example. She grew up during World War II so she had a sense of history that again many younger do not.
Yes, and when she attended the memorial service in D.C. at the National Cathedral, she sang our National Anthem, word for word, without having to reference it in writing. It was very touching that she knew the words by heart and joined in.