I agree that it looks great on her, but the constant repetition is somewhat boring. So I'm glad that she has worn both Ena's fleur de lys tiara and the Cartier loop tiara lately. But these two might be a bit over the top for this visit, so the Mellerio shell tiara might be a nice change.
When did she wear the Cartier loop ? I recall her wearing Ena’s Pearl and Diamond tiara, but not the Cartier Loop.