Why does she not want to be my girlfriend?

Ok, so I have been talking to this girl Ashleigh for about a month now and we talk everyday and see each other quite often. When we hang out we have a great time and never want it to end. I have a tendency to get attached to someone very quickly so my feelings for her are very strong right now. I asked her to be my girlfriend but her response was "Aww Seth, I think your a great guy but right now I'm just looking for a friendship". The problem is that I don't think that is true because she is very affectionate towards me. Could she just be scared of being in a relationship or having that title so to say? We hold hands when we go on walks and hug all the time, I just don't understand why she is scared of making the commitment.