She ignored your invite but still responded positively. There could be several reasons why:
I'm guessing she avoided your invite because you didn't give her enough options of when to meet up and you made the invite before you created enough interest to meet.
In your situation, I'd recommend responding with a playful message referencing the topic she brought up. If she responds positively to that, then you can invite her again. This time with a more playful vibe and with more time options.