"An important thing is what is going on in your life now?
Do you have a partner? Have you recently ended a relationship? Are you feeling lonely? Do you miss your younger years? Are you having marital problems?"

No, everything was normal prior to the dream and intense thinking of her. 

"If that is not the case, then probably it might be that she is thinking about you. Probably she is not feeling happy, or has some marital issues." 

5 days ago, I made a simply phone call asking for her updated email address.  In the call, she seemed quite happy with everything.  I then emailed her telling what I was experiencing, addressing previous relationship issues, and informing about my recent life, without asking her to do anything. I was hoping that the email would help resolve the issue, leaving me in peace. She hasn't responded yet.

This is my guess of what is going on:  At the conscious level, she is my former lover who I no longer attach to. At the subconscious level, where true feelings lie, I still love her dearly. This true feeling is pouring out now, accounting for my experience.  I believe in synchronicity, but I don't know why now.   Perhaps, as you suggest, it may have to do with her side.

Do you think my guess is "right"?