How to find Jessica?

I'm a 67 year old male. My girlfriend that I met at Trout Lake YMCA in 1963-1964 named Jessica has not called me even though I gave her my number. Of course since mobile phones took over in the 2000s and I moved out of my parent's home in '74, a little bit after I got back from Vietnam, what chance would she have known my new phone numbers? I know she loves me though and I want to marry her. I know it is 50 years later but I don't even care. Her blonde hair was gorgeous. How do I find her?