Most people will tell you to get it off your chest. Although it
is true in some sense, you don't really have to tell her so
directly and especially, so early.
You don't even know if she is good for you. That is the point of
dating. It is to find out what kind of person she is before you
start committing. We all know you like her for her
looks/personality/whatever. So what? Get to know her better and see
if you really like her and see if she is good enough for you.
Always remember you don't need a person to be happy.
But saying all these is useless since she already made it very
clear to you. Just treat it like nothing happened and remember to
smile at her, always, when you see her.