And here's the story of Camilla's visit

Camilla on Royal Visit at Hampstead School

You can see Lena at the left in this picture, gazing at the Duchess of Cornwall. She got to have a short conversation with her, Camilla asking her if there were many Americans in the school (she pegged Lena's accent immediately, evidently). Later in the day, when she saw Lena again, she said "Here's my American friend."