She asked me to think about what to do, and how should I reply?

Just say no and be sharp when you say it. It's a little rude, but at least it won't delay each other's time. Pain is just pain! This situation must not be euphemistic, lest the other party think too much, leading to unnecessary troubles in the future and even escalating the situation. There is nothing wrong with liking someone, but it can't disturb your normal life and break the original peace.