<human>: I recently (1 month ago) met someone that is a huge breath of fresh air.  I feel like we've known each other for years. We hit it off extremely well , then suddenly the lines of communication are cut off for a couple days and the only reply after telling her that if something is bothering her, I'm open for discussion, to which she replies "I just need some time"

This is such a conundrum to me since she has been reinforcing how great it's been to finally meet someone like me.  The only thing I can surmise is that she is a little freaked at how fast/well things are moving along and is worried to fall for someone.  

Are there any women that can relate to this situation and give me sound advice as to what could be going through her mind?

Can you summarize the given text in a few sentences?
<bot>: New relationship going extremely well, then suddenly she says "I just need some time" How long should "some time" be?  A week?  A month? What could change her mind so abruptly?