Dear Georgie,
I just wanted to thank you very sincerely for ensuring that everything went smoothly yesterday. The food was delicious and served so discreetly and calmly that everyone was served promptly, and I understand, quiet changes made too. (Sorry if I misled you about any preferences.) I have already had many compliments and thanks for the happy day, and I certainly had a wonderful time. So please pass on my thanks to all your staff, and a particularly warm thanks from me to you.
With thanks and warmest wishes,
Kate