Ever stop and think, just for a sec, that we, as a community, analyze things a little TOO much?
Reading this thread, I just did.
Its a text message guys. If she likes you, it won't matter how fast or slow you answer, how much or little you type, or if you even respond at all. Worry more about how you present yourself when you're actually WITH her. That, in the grand scheme of things, has the greatest effect on her opinion of you.