I'm seeing a girl who I had preliminary feelings for, but now I'm not so sure. What should I do?

I've been seeing a girl more than a couple years older than me for about two weeks now. At first I thought I could really grow to like her and date her. However, now after finding out that she likes me and may be interested and more prepared than I to have a serious relationship, which I wouldn't be able to commit to, I believe it'd be better to just let her go. She likes me more than I like her and I feel as if her feelings for me are too much too soon so I want to be able to end things without hurting her. How should I go about doing so?