I agree the first screw up was inviting her to dinner. Even if you're jumping for joy on the inside, you have to contain that emotion, not even letting it come out in the seemingly meager form of a dinner invitation. I always get their #, never give mine, then keep all the power for myself.

If it was me running into her at the Cafe' later, I would have been asking her when SHE was going to take ME out to dinner, while elaborating that it "better be somewhere nice".

Build value. Keep value.