Ken, I am going to be very straight with you. I think you are reacting to very vulnerable emotions with this younger girl. I'm sure she is attracted to your maturity, but how long do you think it will be before she is ready for someone closer to her age....then you will be facing more pain. You are not over your MR and you don't need to be getting involved with this girl.
It is one thing to go out to a friendly dinner or show.....but if she was acting cold toward you, then she is feeling pressure from you. You need to back off immediately. I think she was trying to be "nice" when she said she was concerned about emotional involvment. She may not want to hurt you and don't know how to get out of this.
It's not fair to her. Do the right thing. Besides, you don't want her looking at you as a father figure.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!