What ever you do, do not say "thank you." It won't go down very well.
You've just got to be honest, we appreciate honesty more than any other bullsh*t excuse that you may think we want to hear. If she says it, tell her you like her a lot but you don't want to say anything extreme at the moment because it's not a word to play around with, you want to be able to genuinely mean it when you say it.
I'm also a cynical one in approach to relationships but that approach has worked for me before now.
Good luck!