I notified an interviewee Friday that we will hire her to start in 3 weeks, over the weekend we got some information and would like to change our mind... Can I do this or are we legally bound to hire her now? No information was signed at all, I only

I notified an interviewee Friday that we will hire her to start in 3 weeks, over the weekend we got some information and would like to change our mind... Can I do this or are we legally bound to hire her now? No information was signed at all, I only called her to notify her...