I need to know if I need to say anything more this girl I want to take out.

The story goes: she adds me on FB (I know...), I accept her request after finding out she has a lot of the same friends I do. A couple hours after accepting her request, I message her saying "I'm not sure if I know you blah blah." she responds saying she sees me walking around on my lunch break all the time. I respond "Oh that was you! blah blah" then she asks me what I'm up to. I immediately ask her out to lunch on Thursday (12 hours from now) and let her know some interesting things I've been up to.

She seems very interested by the conversation, but her responses stopped as soon as I told her what I've been up to and asked her out to lunch. It's been about 30 hours since I sent that last message, and my proposed time for the date is closing in.

My only question is: Do I message her again to confirm her attendance (or lack thereof)? If your advice is to message her, what do I say?