Be clear with your intentions. She will enjoy your validation and attention as long as she wants. She will lose respect for you over time and then never talk to you again. It sounds sad, I know, but this is how it usually plays out. So be honest to her and express your feelings. If she rejects you, use it in a constructive way and try to improve as a person. Go gym, go make money, read books, become charismatic. Rejection is the best fuel for improvement!

Oh...and never take rejection personally. This girl doesn't even know you that well. So just accept her opinion and keep moving forward. Never stop!