Even if she hopes you are moving on so that she does not feel guilty, her happiness should not be tied to your happiness.
Dark is dark. It is counter intuitive to not respond when they are being nice. We often find it is the counter intuitive action that gets the best results.
She could be curious...
Did she ask you a question?
It only sounds like she hoped you have a good time. If you want to respond, respond when you get back... and say... you had a GREAT time...
