Sounds like you have a really cool friend...don't mess it up trying to add more to it by your own design. Have fun...hang out...in time if you two become more than that then it is cool.

The comment:
"You know what would really scare me? Commitment."

Could have been made for sevral different reasons.
1st she sensed your desires and was maybe tying to slow things down.
2nd she was just being honest and talking about personal issues with her. She could have wanted you ask why she felt that way.
3nd she wanted to see how you reacted to the comment.

sounds like honesty is a big part of your friendship...just tell her your thoughts