Since she knows you are interested in her, who knows if she was just lonely, needed assurance, or really interested in you, but she was sure using that shower scene to manipulate you. Sometimes, women find it fascinating to have a man be interested in her and use him to make her feel good about herself. If you want to be sure if she was using that to show interest towards you, you should talk to her. If she makes it sound like she is still not ready for a new relationship or she is not interested in you, that proves she was using you for her self-interest. If she says yes, she is interested in you, then that was her way of conveying her message to you at the shower scene.