the way i see it, if she has those fantasies, you have to step up. you can't make her a sub, but you can be more dominant. talk to her. plan a day to try tieing her up. plan it out. then don't do it.

call her one day. tell her you want her. that you will be there and she is to be ready. tell her what to wear. where to be. and what you will do TO her. then follow through.